Question

我试图在片段中使用手势;我在FragmentActivity中有以下内容来处理我的细节片段。我试图发生的是在视图上检测到滑动以使用上一个或下一个条目替换该视图内的数据。

如果有更好的方法来处理这个问题;我完全同意。但是，这里发生的事情是onFling方法实际上从未被调用过。

public static class DetailsFragment extends Fragment {
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
        if (container == null) {
            return null;
        }
        View v = inflater.inflate(R.layout.my_view, null, false);
        final GestureDetector gesture = new GestureDetector(getActivity(),
            new GestureDetector.SimpleOnGestureListener() {
                @Override
                public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                    float velocityY) {

                    final int SWIPE_MIN_DISTANCE = 120;
                    final int SWIPE_MAX_OFF_PATH = 250;
                    final int SWIPE_THRESHOLD_VELOCITY = 200;
                    try {
                        if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                            return false;
                        if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                            && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                            Log.i(Constants.APP_TAG, "Right to Left");
                        } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                            && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                            Log.i(Constants.APP_TAG, "Left to Right");
                            titles.showDetails(getPosition() - 1);
                        }
                    } catch (Exception e) {
                        // nothing
                    }
                    return super.onFling(e1, e2, velocityX, velocityY);
                }
            });

        v.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return gesture.onTouchEvent(event);
            }
        });

        return v;
    }
}

Answer 1

以下问题似乎解释了这一点：Android: GestureDetector won't catch Gestures

此外，结果如下：

解决方案实际上是覆盖onDown方法并返回true;否则手势检测器将停止并且不会检测到向上：

        final GestureDetector gesture = new GestureDetector(getActivity(),
            new GestureDetector.SimpleOnGestureListener() {

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

                @Override
                public boolean onFling(MotionEvent e1, MotionEvent e2, float velocityX,
                    float velocityY) {
                    Log.i(Constants.APP_TAG, "onFling has been called!");
                    final int SWIPE_MIN_DISTANCE = 120;
                    final int SWIPE_MAX_OFF_PATH = 250;
                    final int SWIPE_THRESHOLD_VELOCITY = 200;
                    try {
                        if (Math.abs(e1.getY() - e2.getY()) > SWIPE_MAX_OFF_PATH)
                            return false;
                        if (e1.getX() - e2.getX() > SWIPE_MIN_DISTANCE
                            && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                            Log.i(Constants.APP_TAG, "Right to Left");
                        } else if (e2.getX() - e1.getX() > SWIPE_MIN_DISTANCE
                            && Math.abs(velocityX) > SWIPE_THRESHOLD_VELOCITY) {
                            Log.i(Constants.APP_TAG, "Left to Right");
                        }
                    } catch (Exception e) {
                        // nothing
                    }
                    return super.onFling(e1, e2, velocityX, velocityY);
                }
            });

        v.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View v, MotionEvent event) {
                return gesture.onTouchEvent(event);
            }
        });

Answer 2

一些评论

我必须按如下方式调整我的代码：

v.setOnTouchListener(new View.OnTouchListener() {
    @Override        
    public boolean onTouch(View v, MotionEvent event) {

        // return gesture.onTouchEvent(event);

        gesture.onTouchEvent(event);
        return true; // <-- this line made the difference
    }
});

此外，如果您使用xml文件来创建视图

View v = inflater.inflate(R.layout.my_view, null, false);

确保您实际按下了预期的视图。夸大测试的一个好方法是将宽度和高度都设置为＆＃34; match_parent＆＃34;而不是＆＃34; wrap_content＆＃34;在你的布局xml文件中。

Android碎片onCreateView with Gestures

2 个答案: