Android的觸摸事件分發是從最上層的Activity開始的，然后dispatch到子View，當分發到觸發事件的View時，再逐層往回調用onTouchEvent函數，下面是實例代碼。（有空還要更徹底的研究下源碼）
1 public class DispatchActivity extends Activity { 2
3 @Override 4 protected void onCreate(Bundle savedInstanceState) { 5 super.onCreate(savedInstanceState); 6
7 View disView = new DispatchView(this); 8 LayoutParams lp = new LayoutParams(LayoutParams.FILL_PARENT, 9 LayoutParams.FILL_PARENT); 10 setContentView(disView, lp); 11 } 12
13 @Override 14 public boolean onTouchEvent(MotionEvent event) { 15 if (event.getAction() == MotionEvent.ACTION_DOWN) { 16 Log.i("()()", "Parent onTouchEvent Down!!!!!!!!!!!!!!!!"); 17 } 18 return super.onTouchEvent(event); 19 } 20
21 @Override 22 public boolean dispatchTouchEvent(MotionEvent ev) { 23 if (ev.getAction() == MotionEvent.ACTION_DOWN) { 24 Log.i("()()", "Parent dispatchTouchEvent Down????????????????"); 25 } 26 return super.dispatchTouchEvent(ev); 27 } 28
29 public class DispatchView extends View { 30
31 private Paint paint = new Paint(); 32
33 public DispatchView(Context context) { 34 super(context); 35 paint.setColor(Color.RED); 36 } 37
38 @Override 39 public boolean dispatchTouchEvent(MotionEvent event) { 40 if (event.getAction() == MotionEvent.ACTION_DOWN) { 41 Log.i("()()", "Child dispatchTouchEvent Down#############"); 42 paint.setColor(Color.BLUE); 43 invalidate(); 44 } 45 return super.dispatchTouchEvent(event); 46 } 47
48 @Override 49 public boolean onTouchEvent(MotionEvent event) { 50 if (event.getAction() == MotionEvent.ACTION_DOWN) { 51 Log.i("()()", "Child onTouchEvent Down*****************"); 52 paint.setColor(Color.GREEN); 53 invalidate(); 54 } 55 return super.onTouchEvent(event); 56 } 57
58 @Override 59 protected void onDraw(Canvas canvas) { 60 canvas.drawRect(30, 30, 300, 300, paint); 61 super.onDraw(canvas); 62 } 63
64 } 65
66 }
實例效果如下：
當點擊紅色的View時，log如下：
如果Child View設置了OnClickListener，那么和在Child View的onTouchEvent函數中返回True是一個效果，也就是此事件不再向上傳播。