Parcerler

GDG Kaohsiung 2017/01/18

Transcript

1. Parceler 2017/01/18 GDGK
2. Guideline Parcelable • Why use parcelable • How use parcelable Parceler 簡介
3. Send string in an intent / bundle Intent intent = new Intent(this, TargetActivity.class); intent.putExtra("intent_name", "york"); startActivity(intent);
4. send object in an intent / bundle Intent intent = new Intent(this, TargetActivity.class); intent.putExtra("intent_user_data", userData); startActivity(intent);
5. Intent intent = new Intent(this, TargetActivity.class); intent.putExtra("intent_user_data", userData); startActivity(intent); send object in an intent / bundle
6. send object in an intent / bundle Intent intent = new Intent(this, TargetActivity.class); intent.putExtra("intent_user_data", userData); startActivity(intent);
7. Serializable http://docs.oracle.com/javase/7/docs/api/java/io/Serializable.html
8. Serializable 實作
9. Serializable 實作 Simplicity
10. Parcelable 實作
11. Parcelable 實作 boilerplate code
12. Serializable vs Parcelable http://www.developerphil.com/parcelable-vs-serializable/
13. Serializable vs Parcelable Serializable Parcelable 效能 低 高 維護性 高 低 用途 stream, file... intent / bundle
14. Other way? @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); UserData userData = MySingleton.getUserData();
15. Other way? @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); UserData userData = MySingleton.getUserData();
16. use global data (static) UserData userData = MySingleton.getUserData(); Benefit： • easy to use • high performance
17. use global data (static) Disadvantage： • high coupling • can’t handle activity life cycle (system kill)
18. Activity Life Cycle
19. Activity Life Cycle system kill
20. Activity Life Cycle Activity A MySingleton.setUserData(userData);
21. Activity Life Cycle Activity A Activity B UserData userData = MySingleton.getUserData();
22. Activity Life Cycle Activity A Activity B UserData userData = MySingleton.getUserData(); // userData is null After system kill
23. 使用時機 • Intent / Bundle • Activity Life Cycle - ◦ system kill ◦ recreate
24. Activity Life Cycle recreate
25. Activity Life Cycle recreate onConfigurationChange • screen orientation • multiple-windows • language change • ...
26. handle recreate @Override protected void onCreate(@Nullable Bundle savedInstanceState) { super.onCreate(savedInstanceState); if (savedInstanceState != null) { userData = savedInstanceState.getParcelable(STATE_USER_DATA); } else { presenter.loadUserData(); } }
27. handle recreate @Override protected void onSaveInstanceState(Bundle outState) { super.onSaveInstanceState(outState); outState.putParcelable(STATE_USER_DATA, userData)); }
28. Parcelable 實作 - 純手動
29. Parcelable 實作 - 半手動 https://github.com/mcharmas/and roid-parcelable-intellij-plugin
30. Parcelable 實作 - 全自動 https://github.com/johncarl81/ parceler
31. Guideline Parcelable Parceler 簡介 • 基本用法 • 進階用法
32. Parceler 基本 用法 @Parcel
33. Parceler 基本用法 Parcels.unwrap() Parcels.wrap()
34. Parceler 基本用法 @Transient
35. Parceler 進階用法 @ParcelConverter
36. Parceler 進階用法 @ParcelConverter
37. Parceler 進階用法 @Parcel(analyze = DetailUserData.class)
38. 更多用法 https://github.com/johncarl81/parceler
39. Q & A