将 Fling 手势添加到图像视图 - Android [英] Adding Fling Gesture to an image view - Android

问题描述

好的，我一直在这里引用代码:网格布局上的Fling手势检测

Okay I have been referencing the code here: Fling gesture detection on grid layout

但就是不能让它工作.在我的主要活动中，我定义了一个简单的图像.我想检测图像上的一扔.下面是我的代码.底部的 onclick 方法是空的.是不是因为这个?我将其留空，因为在其他代码示例中它不是我想要的.我只想弹出一个简单的吐司，说向右或向左.

but just can not get it to work. In my main activity I have a simple image defined. I want to detect a fling on the image. Here is my code below. The onclick method at the bottom is empty. Is it because of this? I left it blank because in the other code sample its not what I want. I just want a simple toast to pop up saying fling right or fling left.

public class GestureRightLeft extends Activity implements OnClickListener  {

    ImageView peek;

    private static final int SWIPE_MIN_DISTANCE = 120;
    private static final int SWIPE_MAX_OFF_PATH = 250;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;
    private GestureDetector gestureDetector;
    View.OnTouchListener gestureListener;

    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);

        peek =(ImageView) findViewById(R.id.peek);
        peek.setImageResource(R.drawable.bluestrip);

        gestureDetector = new GestureDetector(new MyGestureDetector());
        gestureListener = new View.OnTouchListener() {
            public boolean onTouch(View v, MotionEvent event) {
                if (gestureDetector.onTouchEvent(event)) {
                    return true;
                }
                return false;
            }
        };
    }

    class MyGestureDetector extends SimpleOnGestureListener {
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            try {
                if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                    return false;
                // right to left swipe
                if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                    Toast.makeText(GestureRightLeft.this, "Left Swipe", Toast.LENGTH_SHORT).show();
                }  else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                    Toast.makeText(GestureRightLeft.this, "Right Swipe", Toast.LENGTH_SHORT).show();
                }
            } catch (Exception e) {
                // nothing
            }
            return false;
        }
    }

    @Override
    public void onClick(View v) {}
}

推荐答案

这是我能想到的最简单的 flinger 工作版本.实际上，您可以将它绑定到任何组件，而不仅仅是 ImageView.

Here's the simpliest working version of flinger I can think of. You can actually tie it to any component, not only ImageView.

public class MyActivity extends Activity {
    private void onCreate() {
        final GestureDetector gdt = new GestureDetector(new GestureListener());
        final ImageView imageView  = (ImageView) findViewById(R.id.image_view);
        imageView.setOnTouchListener(new OnTouchListener() {
            @Override
            public boolean onTouch(final View view, final MotionEvent event) {
                gdt.onTouchEvent(event);
                return true;
            }
        });
    }               

    private static final int SWIPE_MIN_DISTANCE = 120;
    private static final int SWIPE_THRESHOLD_VELOCITY = 200;

    private class GestureListener extends SimpleOnGestureListener {
        @Override
        public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
            if(e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                return false; // Right to left
            }  else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                return false; // Left to right
            }

            if(e1.getY() - e2.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityY) > SWIPE_THRESHOLD_VELOCITY) {
                return false; // Bottom to top
            }  else if (e2.getY() - e1.getY() > SWIPE_MIN_DISTANCE && Math.abs(velocityY) > SWIPE_THRESHOLD_VELOCITY) {
                return false; // Top to bottom
            }
            return false;
        }
    }
}

虽然 onClickListener 没有活动(如果您不需要捕获任何 onclick 操作)它不仅可以捕获水平，还可以捕获垂直(如果不需要，只需删除垂直部分)，并且水平滑动具有优先级，如您所见.在方法返回的地方(我的评论所在的地方)只需调用您的方法或其他任何东西:)

No activity onClickListener though (if you don't need to catch any onclick actions) It captures not only horizontal, but vertical also (just delete vertical part if you don't need it), and horizontal swipes have priority as you can see. In places where method returns (nad where my comments are) just call your method or whatever :)

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