Android手势在开始屏幕上使用

Question

什么Android Api用于在Android的开始屏幕上向左或向右滚动？

Answer 1

最简单的方法是检测"Fling"手势.android API有一个内置的检测器,用于基本手势,如投掷,滚动,长按,双击,捏缩放等.

该文档可从http://developer.android.com/reference/android/view/GestureDetector.html获得.

你要做的是创建一个GestureDetector实例,覆盖你有兴趣检测手势的视图的onTouchEvent方法,并将MotionEvent传递给GestureDetector.

您还必须提供OnGestureListener实现(最容易将SimpleOnGestureListener扩展)到GestureDetector,它将处理您的所有手势事件.

例:

class MyView extends View
{
    GestureDetector mGestureDetect;

    public MyView(Context context)
    {
        super(context);
        mGestureDetect = new GestureDetector(new SimpleOnGestureListener()
        {

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) 
        {
        //check if the fling was in the direction you were interested in
        if(e1.getX() - e2.getX() > 0)
        {
        //Do something here
        }
        //fast enough?
        if(velocityX > 50)
        {
        //etc etc
        }

        return true;
        }
        }
    }

    public boolean onTouchEvent(MotionEvent ev)
    {
        mGestureDetector.onTocuhEvent(ev);
        return true;
    }
}