onTouchEvent从未调用过MapActivity

Question

I have an activity which extends MapActivity. But when I tap the map, the onTouchEvent never gets called. Why is this?

@Override
public boolean onTouchEvent(MotionEvent event) {
    Log.d("temp", "onTouchEvent");
    return true;
}

edit: I now have these 2 methods in a custum created ItemizedOverlay to catch my events. The first one gets called when I tap an overlay. But the second (onTouchEvent) never get's called when I touch the map.

@Override
    protected boolean onTap(int index) {
      OverlayItem item = mOverlays.get(index);
      this.movement = true;
      Log.d("temp", "overlayItem tapped" + item.getTitle());
      return true;
    }

    @Override
    public boolean onTouchEvent(MotionEvent event, MapView mapView) {
        this.movement = false;
        Log.d("temp", "overlayItem tapped finish");
        return true;
    }

Answer 1

The MapView associated with a MapActivity almost certainly handles the view for you. If you look at the docs for Activity#onTouchEvent() it says: "Called when a touch screen event was not handled by any of the views under it."

http://developer.android.com/reference/android/app/Activity.html#onTouchEvent(android.view.MotionEvent)

I'm guessing what you want to do with that touch event is already handled by the MapView , maybe find the right place to put it inside of that code?

Answer 2

您应该覆盖dispatchTouchEvent

Answer 3

The handler isn't being executed. I didn't find the exact reason for this behavior yet. Probably the reason is that the MapActivity doesn't automatically forward the event to the registered MapView or it just doesn't get notified about the event, since the motion event actually occurs on the MapView itself and not its parent, the MapActivity.

What can be done instead is to either register the event directly on the MapView mapView.setOnTouchListener(new OnTouchListener() {

public boolean onTouch(View v, MotionEvent event) {
  // TODO Auto-generated method stub
   return false;
  }
});

..or to override the MapActivity's dispatchTouchEvent(MotionEvent). What has to be considered however is to appropriately forward the event in this case.