Question

我需要在代码中检测滑动方向。我可以检测到方向，但是如果我向右上方或左上方滑动就好了。同样的左边，我的要求是没有举起手指，如果我向左滑动它应该只剩下，同样所有的方向。谁能帮我吗。提前谢谢！

@覆盖 public boolean onTouchEvent（MotionEvent touchevent）{

    switch (touchevent.getAction()) {
        // when the user first touches the screen we get x and y coordinate
        case MotionEvent.ACTION_DOWN: {
            x1 = touchevent.getX();
            y1 = touchevent.getY();
            break;
        }

        case MotionEvent.ACTION_MOVE: {


            x2 = touchevent.getX();
            y2 = touchevent.getY();


            float deltaX = x2 - x1;


            if (Math.abs(deltaX) > MIN_DISTANCE) {
                // Left to Right swipe action
                if (x2 > x1) {;
                    Log.e("RTL", "Right to Left Swap Performed");
                }

                else {
                    Log.e("LTR", "Left to Right Swap Performed");
                }

            } else {

                if (y2 > y1) {

                    Log.e("UTD", "UP to Down Swap Performed");
                }

                // Right to left swipe action
                else {
                    Log.e("DTU", "Down to UP Swap Performed");
                }
            }
        }
    }
    return false;
}

Answer 1

你应该计算角度，然后决定。如果矢量大于最小距离值，则可以检查角度。

float angle = (float) Math.toDegrees(Math.atan2(y2 - y1, x2 - x1));
if(angle > 45 && angle <= 135) return UP;
else if(angle > 135 && angle <= 225) return LEFT;
else if(angle > 225 && angle <= 315) return DOWN;
else return RIGHT;

Answer 2

创建 GestureDetectorCompat 对象

GestureDetectorCompat gestureDetectorCompat;

并覆盖活动

中的 onTouchEvent

 @Override
        public boolean onTouchEvent(MotionEvent event) {
            gestureDetectorCompat.onTouchEvent(event);
            return true;
        }

或者如果您想在某些视图中进行检测，则可以覆盖 onTouch

someView.setOnTouchListener(new View.OnTouchListener() {
            @Override
            public boolean onTouch(View view, MotionEvent motionEvent) {
                gestureDetectorCompat.onTouchEvent(motionEvent);
                return false;
            }
        });

并初始化gestureDetectorCompat，如下所示，最好在 onCreate（）中完成。

gestureDetectorCompat = new GestureDetectorCompat(this, new GestureDetector.SimpleOnGestureListener() {
        @Override
        public boolean onScroll(MotionEvent e1, MotionEvent e2, float distanceX, float distanceY) {
            float angle = (float) Math.toDegrees(Math.atan2(e1.getY() - e2.getY(), e2.getX() - e1.getX()));

            if (angle > -45 && angle <= 45) {
                Log.d(DEBUG_TAG, "Right to Left swipe performed");
                return true;
            }

            if (angle >= 135 && angle < 180 || angle < -135 && angle > -180) {
                Log.d(DEBUG_TAG, "Left to Right swipe performed");
                return true;
            }

            if (angle < -45 && angle >= -135) {
                Log.d(DEBUG_TAG, "Up to Down swipe performed");
                return true;
            }

            if (angle > 45 && angle <= 135) {
                Log.d(DEBUG_TAG, "Down to Up swipe performed");
                return true;
            }

            return false;
        }


    });

向所有方向滑动手势（左，右，上，下）

2 个答案: