Kotlin Introduction & Google Firebase Integration

Let's get an introduction about Kotlin, the not-so-new language for Android and talk about Firebase for authentication and data storage.

Transcript

1. Kotlin Introduction
 & Google Firebase Integration Jorge E. Hernández
 @lalongooo
 Android Engineer at Unosquare
2. Android?
3. A 5 minutes introduction
4. A 5 minutes introduction // school_file.xml
5. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> 
 // school_file.xml
6. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 </school> // school_file.xml
7. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student /> </school> // school_file.xml
8. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“”/> </school> // school_file.xml
9. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan”/> </school> // school_file.xml
10. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“”/> </school> // school_file.xml
11. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> </school> // school_file.xml
12. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml
13. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
14. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml <?xml version="1.0" encoding="utf-8"?> <library>
 </library>
 
 
 // library_file.xml
15. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“”/> </library>
 
 <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
16. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> </library>
 
 <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
17. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
18. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
19. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school>
 <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
20. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:=““> <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
21. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=““> <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
22. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
23. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student name=“Juan” last_name=“Perez”/> <classroom name=“VIP Classroom”/> <teacher name=“El Barco”/> </school> // school_file.xml // library_file.xml
24. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library>
 <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
25. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:=““> <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
26. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=““> <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
27. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=“http://cusur.com/schema/mylibrary“> <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
28. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=“http://cusur.com/schema/mylibrary“> <book
 name=“Fifty shades of Grey”/> <student
 name=“José García”/> <author
 name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
29. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=“http://cusur.com/schema/mylibrary“> <book
 l:name=“Fifty shades of Grey”/> <student
 l:name=“José García”/> <author
 l:name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
30. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=“http://cusur.com/schema/mylibrary“> <book
 l:name=“Fifty shades of Grey”/> <student
 l:name=“José García”/> <author
 l:name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:guau=“http://cusur.com/schema/myschool“> <student guau:name=“Juan” guau:last_name=“Perez”/> <classroom guau:name=“VIP Classroom”/> <teacher guau:name=“El Barco”/> </school> // school_file.xml // library_file.xml
31. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:miau=“http://cusur.com/schema/mylibrary“> <book
 miau:name=“Fifty shades of Grey”/> <student
 miau:name=“José García”/> <author
 miau:name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:guau=“http://cusur.com/schema/myschool“> <student guau:name=“Juan” guau:last_name=“Perez”/> <classroom guau:name=“VIP Classroom”/> <teacher guau:name=“El Barco”/> </school> // school_file.xml // library_file.xml
32. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <library
 xmlns:l=“http://cusur.com/schema/mylibrary“> <book
 l:name=“Fifty shades of Grey”/> <student
 l:name=“José García”/> <author
 l:name=“E. L. James”/> </library> <?xml version="1.0" encoding="utf-8"?> <school
 xmlns:s=“http://cusur.com/schema/myschool“> <student s:name=“Juan” s:last_name=“Perez”/> <classroom s:name=“VIP Classroom”/> <teacher s:name=“El Barco”/> </school> // school_file.xml // library_file.xml
33. A 5 minutes introduction
34. A 5 minutes introduction Button
35. A 5 minutes introduction Button TextView
36. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout> </android.support.constraint.ConstraintLayout> // my_screen.xml
37. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout android:layout_width="match_parent"> </android.support.constraint.ConstraintLayout> // my_screen.xml
38. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout android:layout_width="match_parent" android:layout_height="match_parent"> </android.support.constraint.ConstraintLayout> // my_screen.xml
39. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> </android.support.constraint.ConstraintLayout> // my_screen.xml
40. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> </android.support.constraint.ConstraintLayout> // my_screen.xml
41. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button /> </android.support.constraint.ConstraintLayout> // my_screen.xml
42. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
43. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
44. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
45. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
46. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
47. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView /> </android.support.constraint.ConstraintLayout> // my_screen.xml
48. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
49. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
50. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
51. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!"/> </android.support.constraint.ConstraintLayout> // my_screen.xml
52. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
53. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
54. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
55. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
56. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
57. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
58. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
59. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
60. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
61. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
62. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
63. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
64. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
65. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
66. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
67. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
68. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
69. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout> // my_screen.xml
70. A 5 minutes introduction
71. A 5 minutes introduction
72. A 5 minutes introduction Activities Services, Permissions
73. A 5 minutes introduction MyClass.java
 MyClass.kt
74. A 5 minutes introduction Android Tests: - Clicks (taps) - Swipes - Pinch (zoom)
75. A 5 minutes introduction Android Tests: - Clicks (taps) - Swipes - Pinch (zoom) Instrumentation tests
76. A 5 minutes introduction Unit Tests: - Classes - Methods
77. A 5 minutes introduction Pictures, images.
 NOT ICONS
78. A 5 minutes introduction Screens layouts
 (XML files)
79. A 5 minutes introduction Menu options
 (XML files)
80. A 5 minutes introduction Launcher icons
81. A 5 minutes introduction
82. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> </resources>
83. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color></color> </resources>
84. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name=""></color> </resources>
85. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red"></color> </resources>
86. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> </resources>
87. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources>
88. A 5 minutes introduction
89. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> </resources>
90. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <dimen></dimen> </resources>
91. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name=""></dimen> </resources>
92. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width"></dimen> </resources>
93. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> </resources>
94. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
95. A 5 minutes introduction
96. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <string></string> </resources>
97. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <string name=""></string> </resources>
98. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text"></string> </resources>
99. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> </resources>
100. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
101. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout>
102. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto" android:layout_width="match_parent" android:layout_height="match_parent"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> </android.support.constraint.ConstraintLayout>
103. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
104. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
105. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources>
106. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources>
107. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources>
108. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
109. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
110. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
111. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
112. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
113. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
114. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height="wrap_content" android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
115. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
116. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name=“btn_height">100dp</dimen> </resources>
117. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
118. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
119. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text="Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
120. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“Click me" app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
121. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
122. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text="Hello World!" android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
123. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=“Hello World!“ android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
124. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=“@string/hello“ android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
125. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=“@string/hello“ android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name=“hello">Hello World!</string> </resources>
126. A 5 minutes introduction <Button android:id="@+id/myButton" android:layout_width=“@dimen/btn_width" android:layout_height=“@dimen/btn_height” android:text=“@string/btn_text“ app:layout_constraintBottom_toTopOf="@+id/myTextView" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" /> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content" android:text=“@string/hello“ android:textColor=“@color/red" android:textSize="56sp" app:layout_constraintBottom_toBottomOf="parent" app:layout_constraintLeft_toLeftOf="parent" app:layout_constraintRight_toRightOf="parent" app:layout_constraintTop_toTopOf="parent" />
127. my_screen.xml A 5 minutes introduction
128. my_screen.xml A 5 minutes introduction colors.xml
129. my_screen.xml A 5 minutes introduction colors.xml dimens.xml
130. my_screen.xml colors.xml dimens.xml strings.xml A 5 minutes introduction
131. my_screen.xml A 5 minutes introduction colors.xml dimens.xml strings.xml
132. my_screen.xml colors.xml dimens.xml strings.xml A 5 minutes introduction
133. my_screen.xml colors.xml dimens.xml strings.xml A 5 minutes introduction
134. A 5 minutes introduction colors.xml
135. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml
136. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml public final class R { public static final class color { }} }}
137. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml public final class R { public static final class color { }} }}
138. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml public final class R { public static final class color { public static final int red=0x7f050002; }} }}
139. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml public final class R { public static final class color { public static final int red=0x7f050002; public static final int green=0x7f050003; public static final int blue=0x7f050004; }} }}
140. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml R.color.red public final class R { public static final class color { public static final int red=0x7f050002; public static final int green=0x7f050003; public static final int blue=0x7f050004; }} }}
141. A 5 minutes introduction <?xml version="1.0" encoding="utf-8"?> <resources> <color name="red">#FF0000</color> <color name="green">#00FF00</color> <color name="blue">#0000FF</color> </resources> colors.xml R.color.red R.color.green R.color.blue public final class R { public static final class color { public static final int red=0x7f050002; public static final int green=0x7f050003; public static final int blue=0x7f050004; }} }}
142. A 5 minutes introduction dimens.xml
143. A 5 minutes introduction dimens.xml <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
144. A 5 minutes introduction dimens.xml public final class R { public static final class dimen { public static final int btn_width=0x7f030004; public static final int btn_height=0x7f050002; }} }} <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
145. A 5 minutes introduction dimens.xml R.dimen.btn_width R.dimen.btn_height public final class R { public static final class dimen { public static final int btn_width=0x7f030004; public static final int btn_height=0x7f050002; }} }} <?xml version="1.0" encoding="utf-8"?> <resources> <dimen name="btn_width">180dp</dimen> <dimen name="btn_height">100dp</dimen> </resources>
146. A 5 minutes introduction strings.xml
147. A 5 minutes introduction strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
148. A 5 minutes introduction strings.xml <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources> public final class R { public static final class string { public static final int btn_text=0x7f05001e; public static final int hello=0x7f050030; }} }}
149. A 5 minutes introduction strings.xml R.string.btn_text R.string.hello public final class R { public static final class string { public static final int btn_text=0x7f05001e; public static final int hello=0x7f050030; }} }} <?xml version="1.0" encoding="utf-8"?> <resources> <string name="btn_text">Click me</string> <string name="hello">Hello World!</string> </resources>
150. A 5 minutes introduction my_screen.xml
151. A 5 minutes introduction my_screen.xml <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
152. A 5 minutes introduction my_screen.xml public final class R { public static final class layout { public static final int my_screen=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
153. A 5 minutes introduction my_screen.xml R.layout.btn_text R.layout.hello public final class R { public static final class layout { public static final int my_screen=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
154. A 5 minutes introduction my_screen.xml <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
155. A 5 minutes introduction my_screen.xml public final class R { }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
156. A 5 minutes introduction my_screen.xml public final class R { public static final class id { }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
157. A 5 minutes introduction my_screen.xml public final class R { public static final class id { public static final int myButton=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
158. A 5 minutes introduction my_screen.xml public final class R { public static final class id { public static final int myButton=0x7f64003e; public static final int myTextView=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
159. A 5 minutes introduction my_screen.xml R.id.myButton public final class R { public static final class id { public static final int myButton=0x7f64003e; public static final int myTextView=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
160. A 5 minutes introduction my_screen.xml R.id.myButton R.id.myTextView public final class R { public static final class id { public static final int myButton=0x7f64003e; public static final int myTextView=0x7f64003e; }} }} <?xml version="1.0" encoding="utf-8"?> <android.support.constraint.ConstraintLayout xmlns:android="http://schemas.android.com/apk/res/android" xmlns:app="http://schemas.android.com/apk/res-auto"> <Button android:id="@+id/myButton" android:layout_width="wrap_content" android:layout_height="wrap_content"/> <TextView android:id="@+id/myTextView" android:layout_width="wrap_content" android:layout_height="wrap_content"/> </android.support.constraint.ConstraintLayout>
161. A 5 minutes introduction
162. A 5 minutes introduction class MyActivity {{ }}
163. A 5 minutes introduction class MyActivity : Activity() {{ }}
164. A 5 minutes introduction import android.app.Activity class MyActivity : Activity() {{ }}
165. A 5 minutes introduction import android.app.Activity class MyActivity : Activity() {{ override fun onCreate() { }} }}
166. A 5 minutes introduction import android.app.Activity class MyActivity : Activity() {{ override fun onCreate(savedInstanceState: Bundle?) { }} }}
167. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() {{ override fun onCreate(savedInstanceState: Bundle?) { }} }}
168. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() {{ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate() }} }}
169. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() {{ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) }} }}
170. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() {{ override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView() }} }}
171. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }}
172. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }}
173. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }}
174. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.); }} }} MainActivity.kt MainActivity.java
175. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.); }} }} MainActivity.kt MainActivity.java
176. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.); }} }} MainActivity.kt MainActivity.java
177. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.); }} }} MainActivity.kt MainActivity.java
178. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate() { }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate() { }} }} MainActivity.kt MainActivity.java
179. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { }} }} MainActivity.kt MainActivity.java
180. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.); }} }} MainActivity.kt MainActivity.java
181. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} import android.app.Activity import android.os.Bundle public class MyActivity extends Activity { @Override protected void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.my_screen); }} }} MainActivity.kt MainActivity.java
182. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) }} }} MainActivity.kt
183. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById() }} }} MainActivity.kt
184. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>() }} }} MainActivity.kt
185. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton) }} }} MainActivity.kt
186. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { }} }} }} MainActivity.kt
187. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if () { }} }} }} }} MainActivity.kt
188. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if () { // Show }} }} }} }} MainActivity.kt
189. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if () { // Show } else { }} }} }} }} MainActivity.kt
190. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if () { // Show } else { // Hide }} }} }} }} MainActivity.kt
191. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>()) { // Show } else { // Hide }} }} }} }} MainActivity.kt
192. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView)) { // Show } else { // Hide }} }} }} }} MainActivity.kt
193. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility) { // Show } else { // Hide }} }} }} }} MainActivity.kt
194. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility == View.VISIBLE) { // Show } else { // Hide }} }} }} }} MainActivity.kt
195. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility == View.VISIBLE) { findViewById<View>(R.id.myTextView).visibility } else { // Hide }} }} }} }} MainActivity.kt
196. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility == View.VISIBLE) { findViewById<View>(R.id.myTextView).visibility = View.INVISIBLE } else { // Hide }} }} }} }} MainActivity.kt
197. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility == View.VISIBLE) { findViewById<View>(R.id.myTextView).visibility = View.INVISIBLE } else { findViewById<View>(R.id.myTextView).visibility }} }} }} }} MainActivity.kt
198. A 5 minutes introduction import android.app.Activity import android.os.Bundle class MyActivity : Activity() { override fun onCreate(savedInstanceState: Bundle?) { super.onCreate(savedInstanceState) setContentView(R.layout.my_screen) findViewById<View>(R.id.myButton).setOnClickListener { if (findViewById<View>(R.id.myTextView).visibility == View.VISIBLE) { findViewById<View>(R.id.myTextView).visibility = View.INVISIBLE } else { findViewById<View>(R.id.myTextView).visibility = View.VISIBLE }} }} }} }} MainActivity.kt
200. Questions?