重写SurfaceView 的 onTouchEvent实现拖动

public boolean onTouchEvent(MotionEvent event) {float npx = event.getX();float npy = event.getY();switch(event.getAction()){case MotionEvent.ACTION_DOWN:Rect r = new Rect((int) (x-1), (int) (y-1), (int) (x+strWidth+2), (int) (y+ 20));if(r.contains((int)npx, (int)npy)){//人为控制物体isControlByFigner = true;offFignerX = npx - x + 1;offFignerY = npy - y + 1;}break;case MotionEvent.ACTION_MOVE:if(isControlByFigner){//跟随手指x = npx - offFignerX +1;y = npx - offFignerY +1;//计算时差timeOffset = System.currentTimeMillis() - timeRecord;timeRecord = System.currentTimeMillis();}break;case MotionEvent.ACTION_UP:if(isControlByFigner){//计算释放时的速度Vx = (npx - opx)/timeOffset;Vx = (npy - opy)/timeOffset;//释放手指isControlByFigner = false;}break;}opx = npy;opy = npy;this.invalidate();return super.onTouchEvent(event);}