滑动 View 的五种方法

    @Override  
    public boolean onTouchEvent(MotionEvent event) {  
        int x = (int) event.getX();  
        int y = (int) event.getY();  
        switch (event.getAction()){  
            case MotionEvent.ACTION_DOWN:  
                //记录触摸到坐标  
                lastX = x;  
                lastY = y;  
                break;  
            case MotionEvent.ACTION_MOVE:  
                //记录偏移量坐标  
                int offsetX = x - lastX;  
                int offsetY = y - lastY;  
                //在当前的left top right bottom 上加上偏移量  
               /* 方法一： 
               mImageView.layout(mImageView.getLeft()+offsetX,mImageView.getTop()+offsetY, 
                        mImageView.getRight()+offsetX,mImageView.getBottom()+offsetY);*/  
                Log.i("ACTION_MOVE","----x "+offsetX+"---y "+offsetY);  
                /* 
                方法二： 
                mImageView.offsetLeftAndRight(offsetX); 
                mImageView.offsetTopAndBottom(offsetY); 
                */  
                /* 
                方法三： 
                ViewGroup.MarginLayoutParams layoutParams = (ViewGroup.MarginLayoutParams) mImageView.getLayoutParams(); 
                layoutParams.leftMargin += offsetX; 
                layoutParams.topMargin += offsetY; 
                mImageView.setLayoutParams(layoutParams); 
                */  
              /*  方法四： 
                RelativeLayout.LayoutParams layoutParams = (RelativeLayout.LayoutParams) mImageView.getLayoutParams(); 
                Log.i("params"," left:"+mImageView.getLeft()+"  top:"+mImageView.getTop()); 
                layoutParams.leftMargin += offsetX; 
                layoutParams.topMargin += offsetY; 
                mImageView.setLayoutParams(layoutParams);*/  
                /*方法五 
                这个需要使用View所在的ViewGroup中来使用scrollBy方法 
                ((View)mImageView.getParent()).scrollBy(-offsetX,-offsetY); 
                */  
                //重新设置初始坐标  
                lastX = x;  
                lastY = y;  
                break;  
        }  
        return super.onTouchEvent(event);  
    }