Android監測手指上下左右滑動屏幕

在開發android程序時，有時會需要監測手指滑動屏幕，當手指朝上下左右不同方向滑動時做出不同的響應，那怎麼去實現呢？

利用Android提供的手勢監測器就可以很方便的實現，直接上代碼（已測試通過）

public class CbMainActivity extends Activity implements  android.view.GestureDetector.OnGestureListener
{
	//定義手勢檢測器實例
	GestureDetector detector;
	
    @Override
    protected void onCreate(Bundle savedInstanceState)
    {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.cb_main);
        //創建手勢檢測器
        detector = new GestureDetector(this,this); 
    }

    //將該activity上的觸碰事件交給GestureDetector處理
    public boolean onTouchEvent(MotionEvent me){
    	return detector.onTouchEvent(me);
    }
    
	@Override
	public boolean onDown(MotionEvent arg0) {
		return false;
	}

	/**
	 * 滑屏監測
	 * 
	 */
	@Override
	public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
		float minMove = 120;         //最小滑動距離
		float minVelocity = 0;      //最小滑動速度
		float beginX = e1.getX();     
		float endX = e2.getX();
		float beginY = e1.getY();     
		float endY = e2.getY();
		
		if(beginX-endX>minMove&&Math.abs(velocityX)>minVelocity){   //左滑
			Toast.makeText(this,velocityX+"左滑",Toast.LENGTH_SHORT).show();
		}else if(endX-beginX>minMove&&Math.abs(velocityX)>minVelocity){   //右滑
			Toast.makeText(this,velocityX+"右滑",Toast.LENGTH_SHORT).show();
		}else if(beginY-endY>minMove&&Math.abs(velocityY)>minVelocity){   //上滑
			Toast.makeText(this,velocityX+"上滑",Toast.LENGTH_SHORT).show();
		}else if(endY-beginY>minMove&&Math.abs(velocityY)>minVelocity){   //下滑
			Toast.makeText(this,velocityX+"下滑",Toast.LENGTH_SHORT).show();
		}
		
		return false;
	}

	@Override
	public void onShowPress(MotionEvent arg0) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public boolean onSingleTapUp(MotionEvent arg0) {
		// TODO Auto-generated method stub
		return false;
	}

	@Override
	public void onLongPress(MotionEvent arg0) {
		// TODO Auto-generated method stub
		
	}

	@Override
	public boolean onScroll(MotionEvent e1, MotionEvent e2, float velocityX,
			float velocityY) {
	
		return false;
	}

}