Android随笔之手势检测

android为手势检测提供了一个GestureDetector类，其实例代表了一个手势检测器。创建GestureDetector时需要传入一个GestureDetector.OnGestureListener实例作为一个监听器，负责对用户的手势行为提供响应。

  使用android手势检测需要如下两个步骤：

创建一个GestureDetector对象，创建该对象时必须实现一个GestureDetector.OnGestureListener监听器实例

为应用程序的Activity的TouchEvent事件绑定监听器，在事件处理中指定把Activity上的TouchEvent事件交由GestureDetector处理

{

//定义手势监听器实例

GestureDetector detector;

@Override

protected void onCreate(Bundle savedInstanceState)

{

super.onCreate(savedInstanceState);

setContentView(R.layout.activity_main);

//创建手势检测器

detector=new GestureDetector(this,this);

}

//将该Activity上的触碰事件交给GestureDetector处理

@Override

public boolean onTouchEvent(MotionEvent event)

{

return detector.onTouchEvent(event);

}

@Override

public boolean onDown(MotionEvent event)

{

Toast.makeText(this,"onDown",Toast.LENGTH_LONG).show();

return true;

}

@Override

public boolean onFling(MotionEvent event1, MotionEvent event2, float velocityX, float velocityY)

{

        Toast.makeText(this,"onFling", Toast.LENGTH_LONG).show();

return true;

}

@Override

public void onLongPress(MotionEvent event)

{

        Toast.makeText(this,"onLongPress", Toast.LENGTH_LONG).show();

}

@Override

public boolean onScroll(MotionEvent event1, MotionEvent event2, float distanceX,float distanceY)

{

        Toast.makeText(this,"onScroll",Toast.LENGTH_LONG).show();

return true;

}

@Override

public void onShowPress(MotionEvent event)

{

        Toast.makeText(this,"onShowPress", Toast.LENGTH_LONG).show();

}

@Override

public boolean onSingleTapUp(MotionEvent event)

{

        Toast.makeText(this,"onSingleTapUp", Toast.LENGTH_LONG).show();

return true;

}

}