Why onDraw is not called after invalidate()?
Borrowing from the link @
Android Custom Layout - onDraw() never gets called
Try the below it works
1.If you're extending a ViewGroup (in your case a RelativeLayout
) you should override dispatchDraw()
instead of onDraw()
.
Discussion on the topic @
https://groups.google.com/forum/?fromgroups=#!topic/android-developers/oLccWfszuUo
protected void dispatchDraw (Canvas canvas)
Called by draw to draw the child views. This may be overridden by derived classes to gain control just before its children are drawn (but after its own view has been drawn).
Parameters
canvas the canvas on which to draw the view
Example
public class Hello extends Activity {
private MyView myView;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
super.onCreate(savedInstanceState);
Log.e("hello", "hello");
this.myView = new MyView(this);
setContentView(this.myView);
}
public class MyView extends RelativeLayout
{
private Paint myPaint = new Paint();
private int[] numbers;
public MyView(Context paramContext)
{
super(paramContext);
Log.e("MyView", "MyView");
setFocusable(true);
setBackgroundResource(R.drawable.ic_launcher);
}
@Override
protected void dispatchDraw(Canvas canvas){
super.dispatchDraw(canvas);
Log.i("...............","drawing");
}
}
}
2.If you Override onDraw
in the constructor call setWillNotDraw(false)
then it should work.
http://developer.android.com/reference/android/view/View.html#setWillNotDraw(boolean)
public MyView(Context context) {
super(context);
sContext = context;
init();
setWillNotDraw(false);
}
By default all ViewGroup sub-classes do not call their onDraw
method, you should enable it by calling setWillNotDraw(false)
link