我想让飞的手势检测工作在我的Android应用程序。

我有一个GridLayout,包含9个ImageViews。来源可以在这里找到:罗曼家伙的网格布局。

我从Romain Guy的Photostream应用程序中获取的文件只做了轻微的修改。

对于简单的点击情况,我只需要为每个ImageView设置onClickListener,我添加为实现View.OnClickListener的主要活动。实现能够识别投掷的东西似乎要复杂得多。我猜这是因为它可能跨越不同的观点?

If my activity implements OnGestureListener I don't know how to set that as the gesture listener for the Grid or the Image views that I add. public class SelectFilterActivity extends Activity implements View.OnClickListener, OnGestureListener { ... If my activity implements OnTouchListener then I have no onFling method to override (it has two events as parameters allowing me to determine if the fling was noteworthy). public class SelectFilterActivity extends Activity implements View.OnClickListener, OnTouchListener { ... If I make a custom View, like GestureImageView that extends ImageView I don't know how to tell the activity that a fling has occurred from the view. In any case, I tried this and the methods weren't called when I touched the screen.

我真的需要一个跨视图工作的具体例子。我应该在什么时候以及如何附加这个侦听器?我还需要能够检测单个点击。

// Gesture detection
mGestureDetector = new GestureDetector(this, new GestureDetector.SimpleOnGestureListener() {

    public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX, float velocityY) {
        int dx = (int) (e2.getX() - e1.getX());
        // don't accept the fling if it's too short
        // as it may conflict with a button push
        if (Math.abs(dx) > MAJOR_MOVE && Math.abs(velocityX) > Math.absvelocityY)) {
            if (velocityX > 0) {
                moveRight();
            } else {
                moveLeft();
            }
            return true;
        } else {
            return false;
        }
    }
});

是否有可能在我的屏幕上方放置一个透明的视图来捕捉投掷?

如果我选择不从XML膨胀我的子图像视图,我可以通过手势检测器作为构造函数参数到我创建的ImageView的新子类吗?

这是一个非常简单的活动,我试图让飞动检测工作:SelectFilterActivity(改编自photostream)。

我一直在看这些资料:

检测手势-教程 SDK文档 计算器的代码

到目前为止,什么都没用,我希望能得到一些指导。


当前回答

上面的一个答案提到了处理不同的像素密度,但建议手动计算滑动参数。值得注意的是,你可以使用ViewConfiguration类从系统中获得合理的缩放值:

final ViewConfiguration vc = ViewConfiguration.get(getContext());
final int swipeMinDistance = vc.getScaledPagingTouchSlop();
final int swipeThresholdVelocity = vc.getScaledMinimumFlingVelocity();
final int swipeMaxOffPath = vc.getScaledTouchSlop();
// (there is also vc.getScaledMaximumFlingVelocity() one could check against)

我注意到,使用这些值可以使应用程序和系统其他部分之间的“感觉”更加一致。

其他回答

感谢幕府将军,他的代码我适应了我的情况。

让你的活动像往常一样实现onclicklistener:

public class SelectFilterActivity extends Activity implements OnClickListener {

  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
  protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);

    /* ... */

    // Gesture detection
    gestureDetector = new GestureDetector(this, new MyGestureDetector());
    gestureListener = new View.OnTouchListener() {
      public boolean onTouch(View v, MotionEvent event) {
        return gestureDetector.onTouchEvent(event);
      }
    };

  }

  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(SelectFilterActivity.this, "Left Swipe", Toast.LENGTH_SHORT).show();
        } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
          Toast.makeText(SelectFilterActivity.this, "Right Swipe", Toast.LENGTH_SHORT).show();
        }
      } catch (Exception e) {
         // nothing
      }
      return false;
    }

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

将你的手势监听器附加到你添加到主布局中的所有视图上;

// Do this for each view added to the grid
imageView.setOnClickListener(SelectFilterActivity.this); 
imageView.setOnTouchListener(gestureListener);

敬畏地看着你被覆盖的方法被击中,包括activity的onClick(View v)和手势监听器的onFling。

public void onClick(View v) {
  Filter f = (Filter) v.getTag();
  FilterFullscreenActivity.show(this, input, f);
}

“抛舞”后的舞蹈是可选的,但也是鼓励的。

如果有人想要一个可工作的实现,这是上面两个答案的组合。

package com.yourapplication;

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

public abstract class OnSwipeListener implements View.OnTouchListener {

    private final GestureDetector gestureDetector;

    public OnSwipeListener(Context context){
        gestureDetector = new GestureDetector(context, new OnSwipeGestureListener(context));
        gestureDetector.setIsLongpressEnabled(false);
    }

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

    private final class OnSwipeGestureListener extends GestureDetector.SimpleOnGestureListener {

        private final int minSwipeDelta;
        private final int minSwipeVelocity;
        private final int maxSwipeVelocity;

        private OnSwipeGestureListener(Context context) {
            ViewConfiguration configuration = ViewConfiguration.get(context);
            // We think a swipe scrolls a full page.
            //minSwipeDelta = configuration.getScaledTouchSlop();
            minSwipeDelta = configuration.getScaledPagingTouchSlop();
            minSwipeVelocity = configuration.getScaledMinimumFlingVelocity();
            maxSwipeVelocity = configuration.getScaledMaximumFlingVelocity();
        }

        @Override
        public boolean onDown(MotionEvent event) {
            // Return true because we want system to report subsequent events to us.
            return true;
        }

        // NOTE: see http://stackoverflow.com/questions/937313/android-basic-gesture-detection
        @Override
        public boolean onFling(MotionEvent event1, MotionEvent event2, float velocityX,
                               float velocityY) {

            boolean result = false;
            try {
                float deltaX = event2.getX() - event1.getX();
                float deltaY = event2.getY() - event1.getY();
                float absVelocityX = Math.abs(velocityX);
                float absVelocityY = Math.abs(velocityY);
                float absDeltaX = Math.abs(deltaX);
                float absDeltaY = Math.abs(deltaY);
                if (absDeltaX > absDeltaY) {
                    if (absDeltaX > minSwipeDelta && absVelocityX > minSwipeVelocity
                            && absVelocityX < maxSwipeVelocity) {
                        if (deltaX < 0) {
                            onSwipeLeft();
                        } else {
                            onSwipeRight();
                        }
                    }
                    result = true;
                } else if (absDeltaY > minSwipeDelta && absVelocityY > minSwipeVelocity
                        && absVelocityY < maxSwipeVelocity) {
                    if (deltaY < 0) {
                        onSwipeTop();
                    } else {
                        onSwipeBottom();
                    }
                }
                result = true;
            } catch (Exception e) {
                e.printStackTrace();
            }
            return result;
        }
    }

    public void onSwipeLeft() {}

    public void onSwipeRight() {}

    public void onSwipeTop() {}

    public void onSwipeBottom() {}
}

所有人:不要忘记case MotionEvent。ACTION_CANCEL:

它调用30%的滑动没有ACTION_UP

在这里它等于ACTION_UP

上面的滑动手势检测代码非常有用!但是,您可能希望通过使用以下相对值(REL_SWIPE)而不是绝对值(SWIPE_)来使该解决方案密度不可知。

DisplayMetrics dm = getResources().getDisplayMetrics();

int REL_SWIPE_MIN_DISTANCE = (int)(SWIPE_MIN_DISTANCE * dm.densityDpi / 160.0f);
int REL_SWIPE_MAX_OFF_PATH = (int)(SWIPE_MAX_OFF_PATH * dm.densityDpi / 160.0f);
int REL_SWIPE_THRESHOLD_VELOCITY = (int)(SWIPE_THRESHOLD_VELOCITY * dm.densityDpi / 160.0f);

有一个内置的界面,你可以直接使用所有的手势: 下面是对基本级别用户的解释: 有两个进口品在选择时要小心,因为它们都是不同的