android-touch-event

问题 Can we use scale gesture detector for pinch zoom in Android? 回答1: You can use this import android.content.Context; import android.graphics.Canvas; import android.graphics.drawable.BitmapDrawable; import android.util.AttributeSet; import android.util.Log; import android.view.MotionEvent; import android.view.ScaleGestureDetector; import android.view.View; public class MyImageView extends View { private static final int INVALID_POINTER_ID = -1; private Drawable mImage; private float mPosX;

问题 What is the difference between onInterceptTouchEvent and dispatchTouchEvent in Android? According to the android developer guide, both methods can be used to intercept a touch event ( MotionEvent ), but what is the difference? How do onInterceptTouchEvent , dispatchTouchEvent and onTouchEvent interact together within a hierarchy of Views ( ViewGroup )? 回答1: The best place to demystify this is the source code. The docs are woefully inadequate about explaining this. dispatchTouchEvent is