如何处理向下滑动的手势上的ImageView [英] How to handle swipe down gesture on an ImageView

问题描述

我想对一个ImageView的认识向下滑动的手势。我试图 GestureDetector ，但它现在pcated德$ P $。示例code我使用如下。但是，它不会内onFling（）方法。结果

  GestureDetector gestureDetector;
gestureDetector =新GestureDetector（新GestureListener（））;        view.findViewById（R.id.imageView）.setOnTouchListener（新OnTouchListener（）{
            公共布尔onTouch（视图V，MotionEvent事件）{
                如果（gestureDetector.onTouchEvent（事件））{
                    的System.out.println（DONE -------）;
                    updateSwipeAction（）;
                    返回true;
               }
                返回false;
            }
        }）;类GestureListener扩展SimpleOnGestureListener {        私有静态最终诠释SWIPE_MIN_DISTANCE = 10;
        私有静态最终诠释SWIPE_THRESHOLD_VELOCITY = 10;        @覆盖
        公共布尔onFling（MotionEvent E1，E2 MotionEvent，浮velocityX，浮velocityY）{
            如果（e1.getX（） -  e2.getX（）＆GT; SWIPE_MIN_DISTANCE）{
                //从右到左
                返回true;
            }否则如果（e2.getX（） -  e1.getX（）＆GT; SWIPE_MIN_DISTANCE）{
                //从左到右
                返回true;
            }            如果（e1.getY（） -  e2.getY（）＆GT; SWIPE_MIN_DISTANCE）{
                //从底部到顶部
                返回true;
            }否则如果（e2.getY（） -  e1.getY（）＆GT; SWIPE_MIN_DISTANCE）{
                //从上到下
                返回true;
            }
            返回false;
        }        @覆盖
        公共布尔onDown（MotionEvent五）{
            //总是返回true，因为所有的手势总是onDown和＆lt开始; BR＆GT;
            //如果返回false，该框架将不会尝试拿起onFling为例。
            返回true;
        }
    }
 

解决方案

试试这个，实现ongestureListener和那里有一个onscroll方法U可以直接访问

  

@燮pressLint（NewApi）

公共类AndroidExplorer扩展活动实现结果
     android.view.GestureDetector.OnGestureListener

  {
私人处理程序mHandler =新的处理程序（）;
@覆盖
保护无效的onCreate（捆绑mybundle）
{
// TODO自动生成方法存根
super.onCreate（mybundle）;
的setContentView（R.layout.main）;
}
@覆盖
公共布尔onDown（MotionEvent五）{
    // TODO自动生成方法存根
    返回false;
}
@覆盖
公共布尔onFling（MotionEvent E1，E2 MotionEvent，浮velocityX，
        浮动velocityY）{
    // TODO自动生成方法存根
    返回false;
}
@覆盖
公共无效onLong preSS（MotionEvent五）{
    // TODO自动生成方法存根}
@覆盖
公共布尔onScroll（MotionEvent E1，E2 MotionEvent，浮distanceX，
        浮动distanceY）{
    // TODO自动生成方法存根
    返回false;
}
@覆盖
公共无效昂秀preSS（MotionEvent五）{
    // TODO自动生成方法存根}
@覆盖
公共布尔onSingleTapUp（MotionEvent五）{
    // TODO自动生成方法存根
    返回false;
}
 

}

I am trying for recognizing swipe down gesture on an imageview. I tried GestureDetector but it's deprecated now. Sample code I am using is below. But, it's not going inside onFling() method.

GestureDetector gestureDetector;
gestureDetector = new GestureDetector(new GestureListener());

        view.findViewById(R.id.imageView).setOnTouchListener(new OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                if (gestureDetector.onTouchEvent(event)) {
                    System.out.println("DONE-------");
                    updateSwipeAction();
                    return true;
               }
                return false;
            }
        });

class GestureListener extends SimpleOnGestureListener {

        private static final int SWIPE_MIN_DISTANCE = 10;
        private static final int SWIPE_THRESHOLD_VELOCITY = 10;

        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE) {
                //From Right to Left
                return true;
            } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE) {
                //From Left to Right
                return true;
            }

            if (e1.getY() - e2.getY() > SWIPE_MIN_DISTANCE) {
                //From Bottom to Top
                return true;
            } else if (e2.getY() - e1.getY() > SWIPE_MIN_DISTANCE) {
                //From Top to Bottom
                return true;
            }
            return false;
        }

        @Override
        public boolean onDown(MotionEvent e) {
            //always return true since all gestures always begin with onDown and<br>
            //if this returns false, the framework won't try to pick up onFling for example.
            return true;
        }
    }

解决方案

Try this ,Implements ongestureListener and theres a onscroll method u can access directly

@SuppressLint("NewApi")

public class AndroidExplorer extends Activity implements
android.view.GestureDetector.OnGestureListener

{
private Handler mHandler = new Handler();
@Override
protected void onCreate(Bundle mybundle) 
{
// TODO Auto-generated method stub  
super.onCreate(mybundle);
setContentView(R.layout.main);
}
@Override
public boolean onDown(MotionEvent e) {
    // TODO Auto-generated method stub
    return false;
}
@Override
public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
        float velocityY) {
    // TODO Auto-generated method stub
    return false;
}
@Override
public void onLongPress(MotionEvent e) {
    // TODO Auto-generated method stub

}
@Override
public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX,
        float distanceY) {
    // TODO Auto-generated method stub
    return false;
}
@Override
public void onShowPress(MotionEvent e) {
    // TODO Auto-generated method stub

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

}

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