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

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。

其他回答

使用SwipeListView,让它为你处理手势检测。

这个问题仍然存在。添加以下类:

private class SwipeFirstTouchListener implements View.OnTouchListener {

    private final DirtyOnSwipeTouchListener swipe;
    private final View.OnTouchListener delegate;

    private SwipeFirstTouchListener(DirtyOnSwipeTouchListener swipe, View.OnTouchListener delegate) {
        this.swipe = swipe;
        this.delegate = delegate;
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        if (!swipe.onTouch(v, event)) {
            // no a swipe, so lets try with the rest of the events
            return delegate.onTouch(v, event);
        }
        return false;
    }
}

and

private class DirtyOnSwipeTouchListener extends OnSwipeTouchListener {
    private boolean dirty = false;
    private OnSwipeTouchListener delegate;

    public DirtyOnSwipeTouchListener(Context ctx, OnSwipeTouchListener delegate) {
        super(ctx);

        this.delegate = delegate;
    }

    private void reset() {
        dirty = false;
    }

    public void onSwipeTop() {
        dirty = true;

        delegate.onSwipeTop();
    }

    public void onSwipeRight() {
        dirty = true;
        delegate.onSwipeRight();
    }

    public void onSwipeLeft() {
        dirty = true;
        delegate.onSwipeLeft();
    }

    public void onSwipeBottom() {
        dirty = true;
        delegate.onSwipeBottom();
    }

    @Override
    public boolean onTouch(View v, MotionEvent event) {
        try {
            super.onTouch(v, event);

            return dirty;
        } finally {
            dirty = false;
        }

    }
};

还有一个在网上找到的课程:

public class OnSwipeTouchListener implements OnTouchListener {
    
    private static final String TAG = OnSwipeTouchListener.class.getName();

    private final GestureDetector gestureDetector;

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

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

    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 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();
                        }
                        result = true;
                    }
                } else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeBottom();
                    } else {
                        onSwipeTop();
                    }
                    result = true;
                }
            } catch (Exception exception) {
                Log.d(TAG, "Unexpected problem handling swipes, ignoring.", exception);
            }
            return result;
        }
    }

    public void onSwipeRight() {
        // Do nothing
    }

    public void onSwipeLeft() {
        // Do nothing
    }

    public void onSwipeTop() {
        // Do nothing
    }

    public void onSwipeBottom() {
        // Do nothing
    }
}

然后添加你自己的OnTouchListener和OnSwipeTouchListener,如下所示:

    DirtyOnSwipeTouchListener swipe = new DirtyOnSwipeTouchListener(this, new OnSwipeTouchListener(this) {
        public void onSwipeTop() {
            // your code here
        }

        public void onSwipeRight() {
            // your code here
        }

        public void onSwipeLeft() {
            // your code here
        }

        public void onSwipeBottom() {
            // your code here
        }
    });


    View.OnTouchListener toggleListener = new View.OnTouchListener() {
        public boolean onTouch(View v, MotionEvent event) {
            if (event.getAction() == MotionEvent.ACTION_UP) {
                // your code here

                return true;
            } else if (event.getAction() == MotionEvent.ACTION_DOWN) {
                // your code here

                return true;
            }
            return false;
        }
    };

    SwipeFirstTouchListener swipeFirstTouchListener = new SwipeFirstTouchListener(swipe, toggleListener);

    myView.setOnTouchListener(swipeFirstTouchListener);

@Mirek Rusin的回答很好。 但是,有一个小bug,需要修复

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) {
                            if (getOnSwipeListener() != null) {
                                getOnSwipeListener().onSwipeRight();
                            }
                        } else {
                            if (getOnSwipeListener() != null) {
                                getOnSwipeListener().onSwipeLeft();
                            }
                        }
                        result = true;
                    }
                }
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        if (getOnSwipeListener() != null) {
                            getOnSwipeListener().onSwipeBottom();
                        }
                    } else {
                        if (getOnSwipeListener() != null) {
                            getOnSwipeListener().onSwipeTop();
                        }
                    }
                    result = true;
                }

有什么不同?我们设置result = true,仅当我们检查了所有的需求(SWIPE_THRESHOLD和SWIPE_VELOCITY_THRESHOLD都是Ok的)。这是重要的,如果我们放弃滑动,如果一些需求没有实现,我们必须做smth在OnSwipeTouchListener的onTouchEvent方法!

OnSwipeTouchListener.java:

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;

public class OnSwipeTouchListener implements OnTouchListener {

    private final GestureDetector gestureDetector;

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

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

    private final class GestureListener extends 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 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();
                        }
                        result = true;
                    }
                }
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeBottom();
                    } else {
                        onSwipeTop();
                    }
                    result = true;
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }

    public void onSwipeRight() {
    }

    public void onSwipeLeft() {
    }

    public void onSwipeTop() {
    }

    public void onSwipeBottom() {
    }
}

用法:

imageView.setOnTouchListener(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();
    }

});

我一直在做类似的事情,但仅限于水平滑动

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

abstract class OnHorizontalSwipeListener(val context: Context) : View.OnTouchListener {    

    companion object {
         const val SWIPE_MIN = 50
         const val SWIPE_VELOCITY_MIN = 100
    }

    private val detector = GestureDetector(context, GestureListener())

    override fun onTouch(view: View, event: MotionEvent) = detector.onTouchEvent(event)    

    abstract fun onRightSwipe()

    abstract fun onLeftSwipe()

    private inner class GestureListener : GestureDetector.SimpleOnGestureListener() {    

        override fun onDown(e: MotionEvent) = true

        override fun onFling(e1: MotionEvent, e2: MotionEvent, velocityX: Float, velocityY: Float)
            : Boolean {

            val deltaY = e2.y - e1.y
            val deltaX = e2.x - e1.x

            if (Math.abs(deltaX) < Math.abs(deltaY)) return false

            if (Math.abs(deltaX) < SWIPE_MIN
                    && Math.abs(velocityX) < SWIPE_VELOCITY_MIN) return false

            if (deltaX > 0) onRightSwipe() else onLeftSwipe()

            return true
        }
    }
}

然后它可以用于视图组件

private fun listenHorizontalSwipe(view: View) {
    view.setOnTouchListener(object : OnHorizontalSwipeListener(context!!) {
            override fun onRightSwipe() {
                Log.d(TAG, "Swipe right")
            }

            override fun onLeftSwipe() {
                Log.d(TAG, "Swipe left")
            }

        }
    )
}