如何知道ios中的平移手势更改方向？

当我平移手势时，向左移动，然后向右移动。它将正确使用。 我想知道如何知道平移手势改变方向？

试试这个

- (void)panRecognized:(UIPanGestureRecognizer *)rec
{
    CGPoint vel = [rec velocityInView:self.view];
    if (vel.x > 0)
    {
        // user dragged towards the right
        counter++;
    }
    else
    {
        // user dragged towards the left
        counter--;
    }
}

---

在Swift中，我创建了自己的扩展，无论您在哪里都可以使用UIPangestureRecognitor

- (void)handleGesture:(UIPanGestureRecognizer *)gestureRecognizer
{
    CGPoint velocity = [gestureRecognizer velocityInView:yourView];

    if(velocity.x > 0)
    {
        NSLog(@"gesture moving right");
    }
    else
    {
        NSLog(@"gesture moving left");
    }

     if(velocity.y > 0)
    {
        NSLog(@"gesture moving Up");
    }
    else
    {
        NSLog(@"gesture moving Bottom");
    }

}

您可以这样使用：

extension UIPanGestureRecognizer {

    enum GestureDirection {
        case Up
        case Down
        case Left
        case Right
    }

    /// Get current vertical direction
    ///
    /// - Parameter target: view target
    /// - Returns: current direction
    func verticalDirection(target target: UIView) -> GestureDirection {
        return self.velocityInView(target).y > 0 ? .Down : .Up
    }

    /// Get current horizontal direction
    ///
    /// - Parameter target: view target
    /// - Returns: current direction
    func horizontalDirection(target target: UIView) -> GestureDirection {
        return self.velocityInView(target).x > 0 ? .Right : .Left
    }

    /// Get a tuple for current horizontal/vertical direction
    ///
    /// - Parameter target: view target
    /// - Returns: current direction
    func versus(target target: UIView) -> (horizontal: GestureDirection, vertical: GestureDirection) {
        return (self.horizontalDirection(target: target), self.verticalDirection(target: target))
    }

}

---

这段代码使用OptiStart扩展了Luca Davanzo的答案，当您想要处理多个方向的移动时，可以获得正确的结果

Swift 3.1

---

Swift 3

创建手势并将其附加到视图：

let direction = panGestureRecognizer.direction(in: superview)
if direction.contains(.Left) && direction.contains(.Down) {
    // do stuff
} else if direction.contains(.Up) {
    // ...
}

创建将保存最新方向值的类变量：

let panGesture = UIPanGestureRecognizer(target: self, action: #selector(handleGesture))
yourView.addGestureRecognizer(panGesture)

在

yourView

上平移将触发手势处理程序，我们在其中检查平移方向是否已更改：

var latestDirection: Int = 0

这只处理左右平移之间的方向变化，但如果有人想检测上下平移，请将此代码添加到

handleesture

功能：

func handleGesture(gesture: UIPanGestureRecognizer) {
  let velocity = gesture.velocity(in: yourView)
  var currentDirection: Int = 0

  if velocity.x > 0 {
    print("panning right")
    currentDirection = 1
  } else {
    print("panning left")
    currentDirection = 2
  }

  // check if direction was changed
  if currentDirection != latestDirection {
    print("direction was changed")
  }

  latestDirection = currentDirection
}

---

试试这个可能的复制品这个是单方向手指向左移动，然后向右移动，如何判断你改变方向？如果速度（x/y）等于零怎么办？在

func vs（target:）

中，您返回一个具有两个方向的元组，而实际上您有时只能向一个方向移动。您确定会发生这种情况吗？我不确定。。但是，以防万一，我可以通过一个新的手势Direction=>None来改进。这很好，谢谢。尽管用户应该注意，即使从左向右拖动，如果有一点向南的方向，它也会触发。向下。有没有办法降低灵敏度，使它不会触发其他方向？我试着玩速度值，但没用。

var latestDirection: Int = 0

func handleGesture(gesture: UIPanGestureRecognizer) {
  let velocity = gesture.velocity(in: yourView)
  var currentDirection: Int = 0

  if velocity.x > 0 {
    print("panning right")
    currentDirection = 1
  } else {
    print("panning left")
    currentDirection = 2
  }

  // check if direction was changed
  if currentDirection != latestDirection {
    print("direction was changed")
  }

  latestDirection = currentDirection
}

if velocity.y > 0 {
  print("panning down")
} else {
  print("panning up")
}