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

我知道从2012年开始有点晚了,但我希望它能帮助到一些人,因为我认为它比大多数答案都更短,更干净:

view.setOnTouchListener((v, event) -> {
        
int action = MotionEventCompat.getActionMasked(event);

switch(action) {
    case (MotionEvent.ACTION_DOWN) :
        Log.d(DEBUG_TAG,"Action was DOWN");
        return true;

    case (MotionEvent.ACTION_MOVE) :
        Log.d(DEBUG_TAG,"Action was MOVE");
        return true;

    case (MotionEvent.ACTION_UP) :
        Log.d(DEBUG_TAG,"Action was UP");
        return true;

    case (MotionEvent.ACTION_CANCEL) :
        Log.d(DEBUG_TAG,"Action was CANCEL");
        return true;

    case (MotionEvent.ACTION_OUTSIDE) :
        Log.d(DEBUG_TAG,"Movement occurred outside bounds " +
                "of current screen element");
        return true;

    default :
        return super.onTouchEvent(event);
}
    });

当然,你可以只留下相关的手势。

src: https://developer.android.com/training/gestures/detector

其他回答

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
            }
        })
;

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);

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();
    }

});

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。

如果你还需要处理点击事件,这里做一些修改:

public class OnSwipeTouchListener implements OnTouchListener {

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

    public boolean onTouch(final View v, final 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 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) {
                            result = onSwipeRight();
                        } else {
                            result = onSwipeLeft();
                        }
                    }
                } else {
                    if (Math.abs(diffY) > SWIPE_THRESHOLD && Math.abs(velocityY) > SWIPE_VELOCITY_THRESHOLD) {
                        if (diffY > 0) {
                            result = onSwipeBottom();
                        } else {
                            result = onSwipeTop();
                        }
                    }
                }
            } catch (Exception exception) {
                exception.printStackTrace();
            }
            return result;
        }
    }

    public boolean onSwipeRight() {
        return false;
    }

    public boolean onSwipeLeft() {
        return false;
    }

    public boolean onSwipeTop() {
        return false;
    }

    public boolean onSwipeBottom() {
        return false;
    }
}

以及示例用法:

    background.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View arg0) {
            toggleSomething();
        }
    });
    background.setOnTouchListener(new OnSwipeTouchListener() {
        public boolean onSwipeTop() {
            Toast.makeText(MainActivity.this, "top", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeRight() {
            Toast.makeText(MainActivity.this, "right", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeLeft() {
            Toast.makeText(MainActivity.this, "left", Toast.LENGTH_SHORT).show();
            return true;
        }
        public boolean onSwipeBottom() {
            Toast.makeText(MainActivity.this, "bottom", Toast.LENGTH_SHORT).show();
            return true;
        }
    });