我希望我的应用程序能够识别用户在手机屏幕上从右向左滑动。

如何做到这一点?


当前回答

import android.content.Context
import android.view.GestureDetector
import android.view.GestureDetector.SimpleOnGestureListener
import android.view.MotionEvent
import android.view.View
import android.view.View.OnTouchListener

/**
 * Detects left and right swipes across a view.
 */
class OnSwipeTouchListener(context: Context, onSwipeCallBack: OnSwipeCallBack?) : OnTouchListener {

    private var gestureDetector : GestureDetector
    private var onSwipeCallBack: OnSwipeCallBack?=null

    init {

        gestureDetector = GestureDetector(context, GestureListener())
        this.onSwipeCallBack = onSwipeCallBack!!
    }
    companion object {

        private val SWIPE_DISTANCE_THRESHOLD = 100
        private val SWIPE_VELOCITY_THRESHOLD = 100
    }

   /* fun onSwipeLeft() {}

    fun onSwipeRight() {}*/

    override fun onTouch(v: View, event: MotionEvent): Boolean {


        return gestureDetector.onTouchEvent(event)
    }

    private inner class GestureListener : SimpleOnGestureListener() {

        override fun onDown(e: MotionEvent): Boolean {
            return true
        }

        override fun onFling(eve1: MotionEvent?, eve2: MotionEvent?, velocityX: Float, velocityY: Float): Boolean {
            try {
                if(eve1 != null&& eve2!= null) {
                    val distanceX = eve2?.x - eve1?.x
                    val distanceY = eve2?.y - eve1?.y
                    if (Math.abs(distanceX) > Math.abs(distanceY) && Math.abs(distanceX) > SWIPE_DISTANCE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                        if (distanceX > 0)
                            onSwipeCallBack!!.onSwipeLeftCallback()
                        else
                            onSwipeCallBack!!.onSwipeRightCallback()
                        return true
                    }
                }
            }catch (exception:Exception){
                exception.printStackTrace()
            }

            return false
        }


    }
}

其他回答

对@Mirek Rusin的回答做了一点修改,现在你可以检测多点触摸了。这段代码在Kotlin上:

class OnSwipeTouchListener(ctx: Context, val onGesture: (gestureCode: Int) -> Unit) : OnTouchListener {

private val SWIPE_THRESHOLD = 200
private val SWIPE_VELOCITY_THRESHOLD = 200

private val gestureDetector: GestureDetector

var fingersCount = 0

fun resetFingers() {
    fingersCount = 0
}

init {
    gestureDetector = GestureDetector(ctx, GestureListener())
}

override fun onTouch(v: View, event: MotionEvent): Boolean {
    if (event.pointerCount > fingersCount) {
        fingersCount = event.pointerCount
    }
    return gestureDetector.onTouchEvent(event)
}

private inner class GestureListener : SimpleOnGestureListener() {

    override fun onDown(e: MotionEvent): Boolean {
        return true
    }

    override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float): Boolean {
        var result = false
        try {
            val diffY = e2.y - e1.y
            val diffX = e2.x - e1.x
            if (Math.abs(diffX) > Math.abs(diffY)) {
                if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffX > 0) {
                        val gesture = when (fingersCount) {
                            1 -> Gesture.SWIPE_RIGHT
                            2 -> Gesture.TWO_FINGER_SWIPE_RIGHT
                            3 -> Gesture.THREE_FINGER_SWIPE_RIGHT
                            else -> -1
                        }
                        if (gesture > 0) {
                            onGesture.invoke(gesture)
                        }
                    } else {
                        val gesture = when (fingersCount) {
                            1 -> Gesture.SWIPE_LEFT
                            2 -> Gesture.TWO_FINGER_SWIPE_LEFT
                            3 -> Gesture.THREE_FINGER_SWIPE_LEFT
                            else -> -1
                        }
                        if (gesture > 0) {
                            onGesture.invoke(gesture)
                        }
                    }
                    resetFingers()
                }
            } else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                if (diffY > 0) {
                    val gesture = when (fingersCount) {
                        1 ->  Gesture.SWIPE_DOWN
                        2 -> Gesture.TWO_FINGER_SWIPE_DOWN
                        3 -> Gesture.THREE_FINGER_SWIPE_DOWN
                        else -> -1
                    }
                    if (gesture > 0) {
                        onGesture.invoke(gesture)
                    }
                } else {
                    val gesture = when (fingersCount) {
                        1 ->  Gesture.SWIPE_UP
                        2 -> Gesture.TWO_FINGER_SWIPE_UP
                        3 -> Gesture.THREE_FINGER_SWIPE_UP
                        else -> -1
                    }
                    if (gesture > 0) {
                        onGesture.invoke(gesture)
                    }
                }
                resetFingers()
            }
            result = true

        } catch (exception: Exception) {
            exception.printStackTrace()
        }

        return result
    }
}}

在姿态。SWIPE_RIGHT和其他是唯一的整数标识符的手势,我用它来检测一种手势在我的活动:

rootView?.setOnTouchListener(OnSwipeTouchListener(this, {
    gesture -> log(Gesture.parseName(this, gesture))
}))

这里的gesture是一个整型变量它包含了我之前传递的值。

为了添加一个onClick,下面是我所做的。

....
// in OnSwipeTouchListener class

private final class GestureListener extends SimpleOnGestureListener {

    .... // normal GestureListener  code

   @Override
    public boolean onSingleTapConfirmed(MotionEvent e) {
        onClick(); // my method
        return super.onSingleTapConfirmed(e);
    }

} // end GestureListener class

    public void onSwipeRight() {
    }

    public void onSwipeLeft() {
    }

    public void onSwipeTop() {
    }

    public void onSwipeBottom() {
    }

    public void onClick(){ 
    }


    // as normal
    @Override
    public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
}

} // end OnSwipeTouchListener class

我正在使用Fragments,因此使用getActivity()作为上下文。这就是我实现它的方法——而且它很有效。


myLayout.setOnTouchListener(new OnSwipeTouchListener(getActivity()) {
            public void onSwipeTop() {
                Toast.makeText(getActivity(), "top", Toast.LENGTH_SHORT).show();
            }
            public void onSwipeRight() {
                Toast.makeText(getActivity(), "right", Toast.LENGTH_SHORT).show();
            }
            public void onSwipeLeft() {
                Toast.makeText(getActivity(), "left", Toast.LENGTH_SHORT).show();
            }
            public void onSwipeBottom() {
                Toast.makeText(getActivity(), "bottom", Toast.LENGTH_SHORT).show();
            }

            public void onClick(){
                Toast.makeText(getActivity(), "clicked", Toast.LENGTH_SHORT).show();
            }
        });

这个问题很多年前就有人问过了。现在,有一个更好的解决方案:SmartSwipe: https://github.com/luckybilly/SmartSwipe

代码如下所示:

SmartSwipe.wrap(contentView)
        .addConsumer(new StayConsumer()) //contentView stay while swiping with StayConsumer
        .enableAllDirections() //enable directions as needed
        .addListener(new SimpleSwipeListener() {
            @Override
            public void onSwipeOpened(SmartSwipeWrapper wrapper, SwipeConsumer consumer, int direction) {
                //direction: 
                //  1: left
                //  2: right
                //  4: top
                //  8: bottom
            }
        })
;

为了有点击监听器,双击监听器,OnLongPress监听器,向左滑动,向右滑动,向上滑动,在单视图上向下滑动,你需要setOnTouchListener。也就是说,

view.setOnTouchListener(new OnSwipeTouchListener(MainActivity.this) {

            @Override
            public void onClick() {
                super.onClick();
                // your on click here
            }

            @Override
            public void onDoubleClick() {
                super.onDoubleClick();
                // your on onDoubleClick here
            }

            @Override
            public void onLongClick() {
                super.onLongClick();
                // your on onLongClick here
            }

            @Override
            public void onSwipeUp() {
                super.onSwipeUp();
                // your swipe up here
            }

            @Override
            public void onSwipeDown() {
                super.onSwipeDown();
                // your swipe down here.
            }

            @Override
            public void onSwipeLeft() {
                super.onSwipeLeft();
                // your swipe left here.
            }

            @Override
            public void onSwipeRight() {
                super.onSwipeRight();
                // your swipe right here.
            }
        });

}

为此,你需要实现OnTouchListener的OnSwipeTouchListener类。

public class OnSwipeTouchListener implements View.OnTouchListener {

private GestureDetector gestureDetector;

public OnSwipeTouchListener(Context c) {
    gestureDetector = new GestureDetector(c, new GestureListener());
}

public boolean onTouch(final View view, final MotionEvent motionEvent) {
    return gestureDetector.onTouchEvent(motionEvent);
}

private final class GestureListener extends GestureDetector.SimpleOnGestureListener {

    private static final int SWIPE_THRESHOLD = 100;
    private static final int SWIPE_VELOCITY_THRESHOLD = 100;

    @Override
    public boolean onDown(MotionEvent e) {
        return true;
    }

    @Override
    public boolean onSingleTapUp(MotionEvent e) {
        onClick();
        return super.onSingleTapUp(e);
    }

    @Override
    public boolean onDoubleTap(MotionEvent e) {
        onDoubleClick();
        return super.onDoubleTap(e);
    }

    @Override
    public void onLongPress(MotionEvent e) {
        onLongClick();
        super.onLongPress(e);
    }

    // Determines the fling velocity and then fires the appropriate swipe event accordingly
    @Override
    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        boolean result = false;
        try {
            float diffY = e2.getY() - e1.getY();
            float diffX = e2.getX() - e1.getX();
            if (Math.abs(diffX) > Math.abs(diffY)) {
                if (Math.abs(diffX) > SWIPE_THRESHOLD && Math.abs(velocityX) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffX > 0) {
                        onSwipeRight();
                    } else {
                        onSwipeLeft();
                    }
                }
            } else {
                if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeDown();
                    } else {
                        onSwipeUp();
                    }
                }
            }
        } catch (Exception exception) {
            exception.printStackTrace();
        }
        return result;
    }
}

public void onSwipeRight() {
}

public void onSwipeLeft() {
}

public void onSwipeUp() {
}

public void onSwipeDown() {
}

public void onClick() {

}

public void onDoubleClick() {

}

public void onLongClick() {

}
}

扩展Mirek的回答,当你想在滚动视图中使用滑动手势时。默认情况下,滚动视图的触摸监听器被禁用,因此滚动动作不会发生。为了解决这个问题,您需要重写Activity的dispatchTouchEvent方法,并在您完成自己的侦听器后返回该方法的继承版本。

为了对Mirek的代码做一些修改: 我在OnSwipeTouchListener中添加了一个gestureDetector getter。

public GestureDetector getGestureDetector(){
    return  gestureDetector;
}

在Activity中声明OnSwipeTouchListener作为类范围的字段。

OnSwipeTouchListener onSwipeTouchListener;

相应修改用法代码:

onSwipeTouchListener = new OnSwipeTouchListener(MyActivity.this) {
    public void onSwipeTop() {
        Toast.makeText(MyActivity.this, "top", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeRight() {
        Toast.makeText(MyActivity.this, "right", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeLeft() {
        Toast.makeText(MyActivity.this, "left", Toast.LENGTH_SHORT).show();
    }
    public void onSwipeBottom() {
        Toast.makeText(MyActivity.this, "bottom", Toast.LENGTH_SHORT).show();
    }
});

imageView.setOnTouchListener(onSwipeTouchListener);

并覆盖活动内部的dispatchTouchEvent方法:

@Override
    public boolean dispatchTouchEvent(MotionEvent ev){
        swipeListener.getGestureDetector().onTouchEvent(ev); 
            return super.dispatchTouchEvent(ev);   
    }

现在滚动和滑动动作都可以工作了。