Introducción a Kotlin para Android Developers

Una charla introductoria sobre Kotlin para Desarrolladores Android dada en la Kotlin Meetup #01 de Lima Kotlin

Transcript

1. Introducción a Kotlin para Android Developers Armando Picón @devpicon Lima Kotlin
3. Lima Kotlin User Group aka. “Lima Kotlin” Nuestras redes sociales: Twitter @LimaKotlin Facebook: https://www.facebook.com/groups/limakotlin/
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7. Código Java Código Kotlin javac kotlinc bytecode Dalvik ART Android
10. public class Person{ private String name; private int age; public Person(String name, String age){ this.name = name; this.age = age; } public String getName(){ return this.name; } public int getAge(){ return this.age; } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
11. class Persona constructor(name:String, age: Int){ val name = name var age = age } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
12. // Clase simplificada class Persona(val name: String, var age: Int) Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
13. // Data class data class Persona(val name: String, var age: Int) Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
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15. List people = new ArrayList<Person>(); people.add(new Person(“Armando”,35)); people.add(new Person(“Erik”,26)); people.add(new Person(“Adrian”,30)); forEach(Person person: people){ if(person.getName().equals(“Erik”)){ return person; } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
16. val people = listOf<Person>( Person("Adrian", 30), Person("Erik",26), Person("Armando", 35)) val person = people.find { it.name == "Erik" } println(person) Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
17. val numberList = listOf(1, 2, 3, 4, 5) val squared = list.map( i -> i * i) assertTrue(squared.containsAll(listOf(1,4,9,16,25))) squared.forEach { println(it) } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
18. public class MyActivity extends AppCompatActivity{ @Override public void onCreate(Bundle saveInstanceState){ super.onCreate(saveInstanceState); setContentView(R.layout.main_activity); TextView myTextView = (TextView) findViewById(R.id.my_textview); myTextView.setText(“¡Hola Android!”); } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
19. class MyActivity : AppCompatActivity{ override fun onCreate(saveInstanceState:Bundle){ super.onCreate(saveInstanceState); setContentView(R.layout.main_activity); val myTextView = findViewById(R.id.my_textview) as TextView; myTextView.text = “¡Hola kotlin!” } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
20. class MyActivity : AppCompatActivity{ override fun onCreate(saveInstanceState:Bundle){ super.onCreate(saveInstanceState); setContentView(R.layout.main_activity); my_textview.text = “¡Hola kotlin!” } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
21. fun ImageView.loadImage(url: String?){ if(url != null){ Glide.with(this.context) .load(url) .fitCenter() .into(this) } } myImageView.loadImage(“!insert an url here!”) Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
22. var message : String? = null fun sayHello(message:String?){ if(message != null){ println(message) } } Gist: https://gist.github.com/DevPicon/58911d67b05d25106ca3d7699934ce14
23. val adapter: EventAdapter by lazy { initializeAdapter() }
28. ¡Gracias! @devpicon http://medium.com/@devpicon