Android高仿QQ小红点功能

@Overridepublic boolean onTouchEvent(MotionEvent event) {  //获得根View  View rootView = getRootView();  //获得触摸位置在全屏所在位置  float mRawX = event.getRawX();  float mRawY = event.getRawY();  switch (event.getAction()) {    case MotionEvent.ACTION_DOWN:      //请求父View不拦截      getParent().requestDisallowInterceptTouchEvent(true);      //获得当前View在屏幕上的位置      int[] cLocation = new int[2];      getLocationOnScreen(cLocation);      if (rootView instanceof ViewGroup) {        //初始化拖拽时显示的View        dragView = new DragView(getContext());        //设置固定圆的圆心坐标        dragView.setStickyPoint(cLocation[0] + mWidth / 2, cLocation[1] + mHeight / 2, mRawX, mRawY);        //获得缓存的bitmap，滑动时直接通过drawBitmap绘制出来        setDrawingCacheEnabled(true);        Bitmap bitmap = getDrawingCache();        if (bitmap != null) {          dragView.setCacheBitmap(bitmap);          //将DragView添加到RootView中，这样就可以全屏滑动了          ((ViewGroup) rootView).addView(dragView);          setVisibility(INVISIBLE);        }      }      break;    case MotionEvent.ACTION_MOVE:      //请求父View不拦截      getParent().requestDisallowInterceptTouchEvent(true);      if (dragView != null) {        //更新DragView的位置        dragView.setDragViewLocation(mRawX, mRawY);      }      break;    case MotionEvent.ACTION_UP:      getParent().requestDisallowInterceptTouchEvent(false);      if (dragView != null) {        //手抬起时来判断各种情况        dragView.setDragUp();      }      break;  }  return true;}