禁用上下一扔滑動手勢與GestureDetectorCompat

Question

我想先從刷卡向左或向右的手勢在活動的活動，用下面的代碼：

gestureDetector = new GestureDetectorCompat(this, new GestureDetector.SimpleOnGestureListener(){ 
    private static final int SWIPE_THRESHOLD = 50; 
    private static final int SWIPE_VELOCITY_THRESHOLD = 0; 

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

    @Override 
    public boolean onFling(MotionEvent event1, MotionEvent event2, float velocityX, float velocityY) { 
     //user will move forward through messages on fling up or left 
     boolean forward = false; 
     //user will move backward through messages on fling down or right 
     boolean backward = false; 

     //calculate the change in X position within the fling gesture 
     float horizontalDiff = event2.getX() - event1.getX(); 
     //calculate the change in Y position within the fling gesture 
     float verticalDiff = event2.getY() - event1.getY(); 

     float absHDiff = Math.abs(horizontalDiff); 
     float absVDiff = Math.abs(verticalDiff); 
     float absVelocityX = Math.abs(velocityX); 
     float absVelocityY = Math.abs(velocityY); 

     if(absHDiff > absVDiff && absHDiff > SWIPE_THRESHOLD && absVelocityX > SWIPE_VELOCITY_THRESHOLD){ 
      //move forward or backward 
      if(horizontalDiff>0) backward=true; 
      else forward=true; 
     } 
     else if(absVDiff > SWIPE_THRESHOLD && absVelocityY > SWIPE_VELOCITY_THRESHOLD){ 
      if(verticalDiff>0) backward=true; 
      else forward=true; 
     } 

     //user is cycling forward through messages 
     if(forward){ 
      //check current message is not at end of array, increment or set back to start 
      swipeTo(SWIPE_LEFT); 
     } 
     //user is cycling backwards through messages 
     else if(backward){ 
      //check that current message is not at start of array, decrement or set to last message 
      swipeTo(SWIPE_RIGHT); 
     } 

     //return super.onFling(event1, event2, velocityX, velocityY); 
     return true; 
    } 

}); 

如何禁用從動作當滑動垂直時（從上到下或從下往上）時，會採取什麼措施？

SWIPE_LEFT和SWIPE_RIGHT只是分別具有值1和2的類成員常量。

在此先感謝。

Answer 1

我認爲你應該檢測到高值absVelocityY。如果這個值太高，那麼它代表一個垂直投擲。在這些情況下，不要開始新的Activity。