机器人检测到阻力

问题描述：

我一直在玩运动事件和拖动（所以我不会把手指从屏幕上移开 - 这不是一扔）。问题在于它只能检测到第二，第三，第四等，当我的手指移过上下拖动开始和结束点时，拖动向下或向上移动。机器人检测到阻力

查看下面的代码。当我向上拖动时计数等于2，向下拖动时计数为1。然而，只有当我将手指向上移动（计数2），然后再回落到开始向上移动的位置（计数为1）时，才会计数，而不是在等于2之前。我继续向前移动，只有当我移动过去时，我改变了方向才能回落。但是为什么它在这些点之前不认为它是一个阻力，因为在这些方向上的任何移动都应该是一个阻力。我该如何解决这个问题？

这里是我的简单的代码来测试它：

switch (event.getAction()) { 
    case MotionEvent.ACTION_DOWN: 

     oldX = (int) event.getRawX(); 
     oldY = (int) event.getRawY(); 


     break; 

    case MotionEvent.ACTION_MOVE: 

     posY = (int) event.getRawY(); 
     posX = (int) event.getRawX(); 


     diffPosY = posY - oldY; 
     diffPosX = posX - oldX; 

     if (diffPosY > 0){//down 

      count = 1; 

     } 
     else//up 
     { 
      count = 2; 

     } 

     break;

答

如果我明白你正确地做什么，我认为你需要在你的case MotionEvent.ACTION_MOVE:更新oldX和oldY，你使用它后设置diffPosY和diffPosX，因为您当前只在触摸开始时设置了oldX和oldY。所以，你已经设置diffPosY和diffPosX后，添加：

oldX = posX; 
oldY = posY;

UPDATE

由于移动事件频繁处理，你可能要出台一些触摸污占的事实，当您将手指放在屏幕上，您可能会稍微向下移动手指，然后再向上移动而未意识到，如果慢慢地滑动，则可能会以与您想要的方式相反的方向无意中轻微地轻扫。这看起来像你在下面的评论中看到的情况。下面的代码应该有助于解决这个问题，但会对方向变化做出反应稍微慢一点：

// Get the distance in pixels that a touch can move before we 
// decide it's a drag rather than just a touch. This also prevents 
// a slight movement in a different direction to the direction 
// the user intended to move being considered a drag in that direction. 
// Note that the touchSlop varies on each device because of different 
// pixel densities. 
ViewConfiguration vc = ViewConfiguration.get(context); 
int touchSlop = vc.getScaledTouchSlop(); 

// So we can detect changes of direction. We need to 
// keep moving oldY as we use that as the reference to see if we 
// are dragging up or down. 
if (posY - oldY > touchSlop) { 
    // The drag has moved far enough up the Y axis for us to 
    // decide it's a drag, so set oldY to a new position just below 
    // the current drag position. By setting oldY just below the 
    // current drag position we make sure that if while dragging the 
    // user stops their drag and accidentally moves down just by a 
    // pixel or two (which is easily done even when the user thinks 
    // their finger isn't moving), we don't count it as a change of 
    // direction, so we use half the touchSlop figure as a small 
    // buffer to allow a small movement down before we consider it 
    // a change of direction. 
    oldY = posY - (touchSlop/2); 
} else if (posY - oldY < -touchSlop) { 
    // The drag has moved far enough down the Y axis for us to 
    // decide it's a drag, so set oldY to a new position just above 
    // the current drag position. This time, we set oldY just above the 
    // current drag position. 
    oldY = posY + (touchSlop/2); 
}

机器人检测到阻力

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