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

我的解决方案与上述类似,但我将手势处理抽象为一个抽象类OnGestureRegisterListener.java,其中包括滑动、单击和长按手势。

OnGestureRegisterListener.java

public abstract class OnGestureRegisterListener implements View.OnTouchListener {

    private final GestureDetector gestureDetector;
    private View view;

    public OnGestureRegisterListener(Context context) {
        gestureDetector = new GestureDetector(context, new GestureListener());
    }

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

    public abstract void onSwipeRight(View view);
    public abstract void onSwipeLeft(View view);
    public abstract void onSwipeBottom(View view);
    public abstract void onSwipeTop(View view);
    public abstract void onClick(View view);
    public abstract boolean onLongClick(View view);

    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 void onLongPress(MotionEvent e) {
            onLongClick(view);
            super.onLongPress(e);
        }

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

        @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(view);
                        } else {
                            onSwipeLeft(view);
                        }
                        result = true;
                    }
                }
                else if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                    if (diffY > 0) {
                        onSwipeBottom(view);
                    } else {
                        onSwipeTop(view);
                    }
                    result = true;
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }

    }
}

像这样使用它。注意,您还可以轻松地传入您的View参数。

OnGestureRegisterListener onGestureRegisterListener = new OnGestureRegisterListener(this) {
    public void onSwipeRight(View view) {
        // Do something
    }
    public void onSwipeLeft(View view) {
        // Do something
    }
    public void onSwipeBottom(View view) {
        // Do something
    }
    public void onSwipeTop(View view) {
        // Do something
    }
    public void onClick(View view) {
        // Do something
    }
    public boolean onLongClick(View view) { 
        // Do something
        return true;
    }
};

Button button = findViewById(R.id.my_button);
button.setOnTouchListener(onGestureRegisterListener);

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。

@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!

因为这个问题有点老,很流行,我试图更新答案,并通过结合答案和评论中的多种建议来改进它。

从Java切换到Kotlin并使用一些Kotlin语法Eyecandy(主观) 使onswipe函数返回它们是否消耗了事件(ruX答案) 从if语句中移除结果赋值并删除变量(直接返回) 仅检测垂直和水平滑动的替代方案 只能检测上、下、右、左的选择。 为保持一致性(方向,而不是位置),将上下重命名为上下。

四个方向都刷:

open class OnSwipeTouchListener(val context: Context?) : OnTouchListener {
    companion object {
        private const val SwipeThreshold = 100
        private const val SwipeVelocityThreshold = 100
    }

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

    override fun onTouch(v: View, event: MotionEvent): Boolean {
        return gestureDetector.onTouchEvent(event)
    }

    open fun onSwipeRight(): Boolean { return false }
    open fun onSwipeLeft(): Boolean { return false }
    open fun onSwipeUp(): Boolean { return false }
    open fun onSwipeDown(): Boolean { return false }

    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 {
            try {
                val diffY = e2.y - e1.y
                val diffX = e2.x - e1.x

                if (abs(diffX) > abs(diffY)) {
                    if (abs(diffX) > SwipeThreshold && abs(velocityX) > SwipeVelocityThreshold) {
                        return when {
                            diffX > 0 -> onSwipeRight()
                            else -> onSwipeLeft()
                        }
                    }
                } else if (abs(diffY) > SwipeThreshold && abs(velocityY) > SwipeVelocityThreshold) {
                    return when {
                        diffY > 0 -> onSwipeDown()
                        else -> onSwipeUp()
                    }
                }
            } catch (exception: Exception) {
                exception.printStackTrace()
            }
            return false
        }
    }
}

用法:

myView.setOnTouchListener(object : OnSwipeTouchListener(context) {
            // Implement any function you need:
            override fun onSwipeUp(): Boolean {
                Toast.makeText(context, "UP", Toast.LENGTH_SHORT).show()
                return true
            }

            override fun onSwipeLeft(): Boolean {
                Toast.makeText(context, "LEFT", Toast.LENGTH_SHORT).show()
                return true
            }
        })

onFling()的替代方案

替代方案删除更多代码并重新排序检查。重新排序是没有必要的,但我认为它看起来更整洁,更容易理解。 代码将放在try括号中。用法保持不变,只是实现各自的onSwipe函数

水平

val diffY = e2。Y - e1。Y 返回if (abs(velocityY) > SwipeVelocityThreshold) { 当{ > SwipeThreshold -> onSwipeDown() diffY < - swipethreshold -> onSwipeUp() Else -> false } }其他false

垂直

val diffX = e2。X - e1。X 返回if (abs(velocityX) > SwipeVelocityThreshold) { 当{ > SwipeThreshold -> onSwipeRight() diffX < - swipethreshold -> onSwipeLeft() Else -> false } }其他false

一个方向

"up"的例子

val diffY = e2。Y - e1。Y 返回{ diffY < - swipethreshold -> onSwipeUp() Else -> false }

Additional Notes: In (ruX answer) they discussed removing onDown to also detect an onClickListener for the same view. However, when I removed onDown, the class did not work anymore. I don't exactly know why. I looked into the code of GestureDetector but it is very complex and the consequences of the return value of onDown seems to have some implications. So I left it in. Also, you can just use SimpleOnGestureListener.onSingleTapUp() just like you did onFling and create a onClick() function that is called there.

版本信息:

compileSdkVersion 31 minSdkVersion 24 targetSdkVersion 31

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();
    }

});

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
            }
        })
;