Do I need all three constructors for an Android custom view?

by

Long story short, No, but if you do override any constructor, then ensure to call super(...) with the exact same number of arguments (like, see Jin’s answer for example why).

If you will add your custom View from xml also like :

 <com.mypack.MyView
      ...
      />

you will need the constructor public MyView(Context context, AttributeSet attrs), otherwise you will get an Exception when Android tries to inflate your View.

If you add your View from xml and also specify the android:style attribute like :

 <com.mypack.MyView
      style="@styles/MyCustomStyle"
      ...
      />

the 2nd constructor will also be called and default the style to MyCustomStyle before applying explicit XML attributes.

The third constructor is usually used when you want all of the Views in your application to have the same style.

More Related Contents:

  1. Create Passcode view in Android
  2. How to make a swipe strobe..?
  3. Different resolution support android
  4. how to customize snackBar’s layout?
  5. MonoDroid: Error when calling constructor of custom view – TwoDScrollView
  6. Android Custom Shape Button
  7. How is StaticLayout used in Android?
  8. Dynamic height viewpager
  9. Android custom view group delegate addView
  10. How to use isInEditMode() to see layout with custom View in the editor
  11. Android List view layout Similar to Google play
  12. How to make custom dialog with rounded corners in android
  13. No resource identifier found for attribute ‘…’ in package ‘com.app….’
  14. How to remove the top and bottom space on textview of Android
  15. Populate list of custom view using ListFragment
  16. How to get an enum which is created in attrs.xml in code
  17. Making Overlaid image transparent on touch in Android?
  18. Custom PopupMenu (layout)
  19. Android – change custom title view at run time
  20. How can I update a single row in a ListView?
  21. Capture screen shot of GoogleMap Android API V2
  22. Read file As String
  23. Android: Cloning a drawable in order to make a StateListDrawable with filters
  24. Failed to import new Gradle project in android studio
  25. Map Markers with text in Google Maps Android API v2
  26. Firebase Authentication State Change does not fire when user is disabled or deleted
  27. android.content.res.Resources$NotFoundException: String resource ID #0x1 Error [duplicate]
  28. Close/hide the Android Soft Keyboard with Kotlin
  29. How to add submenu items to ActionBar action in code?
  30. How can I programmatically take a screenshot of a webview, capturing the full page?

Leave a Comment