将长按手势和拖动手势结合在一起

Question

我现在正在改变我的观点

UIPanGestureRecognizer *panRecognizer = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(moveRight:)];
[panRecognizer setMinimumNumberOfTouches:1];
[panRecognizer setMaximumNumberOfTouches:1];
[panRecognizer setDelegate:self];
[bubbleView[rightCnt] addGestureRecognizer:panRecognizer];
[panRecognizer release];

，我想通过长按拖动来做同样的事情。

有什么想法吗？

Answer 1

UILongPressGestureRecognizer 已经为您完成了您想要的操作。看一下 UIGestureRecognizerState 属性。来自文档：

长按手势是连续的。手势开始
(UIGestureRecognizerStateBegan)时允许的手指数量
(numberOfTouchesRequired) 已被按下指定的时间
(minimumPressDuration) 并且触摸不会超出
允许的运动范围（allowableMovement）。手势
每当手指移动时，识别器就会转换到更改状态，
当任何手指按下时结束（UIGestureRecognizerStateEnded）
被解除。

因此，基本上在调用 UILongPressGestureRecognizer 选择器之后，您会监听 UIGestureRecognizerStateBegan、UIGestureRecognizerStateChanged、UIGestureRecognizerStateEnded。在 UIGestureRecognizerStateChanged 期间不断更改视图框架。

- (void)moveRight:(UILongPressGestureRecognizer *)gesture
{
    if(gesture.state == UIGestureRecognizerStateBegan)
    {
        //if needed do some initial setup or init of views here
    }
    else if(gesture.state == UIGestureRecognizerStateChanged)
    {
        //move your views here.
        [yourView setFrame:];
    }
    else if(gesture.state == UIGestureRecognizerStateEnded)
    {
        //else do cleanup
    }
}

Answer 2

@implementation MyViewController {
    CGPoint _priorPoint;
}

- (void)moveRight:(UILongPressGestureRecognizer *)sender {
    UIView *view = sender.view;
    CGPoint point = [sender locationInView:view.superview];
    if (sender.state == UIGestureRecognizerStateChanged) {
        CGPoint center = view.center;
        center.x += point.x - _priorPoint.x;
        center.y += point.y - _priorPoint.y;
        view.center = center;
    }
    _priorPoint = point;
}

Answer 3

在 Swift 中，这可以使用下面的代码来实现

class DragView: UIView { 
  // Starting center position
  var initialCenter: CGPoint?

  override func didMoveToWindow() {
    super.didMoveToWindow()
    // Add longPress gesture recognizer
    let longPress = UILongPressGestureRecognizer(target: self, action: #selector(longPressAction(gesture:)))
    addGestureRecognizer(longPress)
  }

  // Handle longPress action
  func longPressAction(gesture: UILongPressGestureRecognizer) {
    if gesture.state == .began {
        guard let view = gesture.view else {
            return
        }
        initialCenter = gesture.location(in: view.superview)
    }
    else if gesture.state == .changed {
        guard let originalCenter = initialCenter else {
            return
        }

        guard let view = gesture.view else {
            return
        }

        let point = gesture.location(in: view.superview)

        // Calculate new center position
        var newCenter = view.center;
        newCenter.x += point.x - originalCenter.x;
        newCenter.y += point.y - originalCenter.y;

        // Update view center
        view.center = newCenter
    }
    else if gesture.state == .ended {
       ...
    }
}

Answer 4

您不需要声明 _priorPoint；

就我而言，我只希望视图水平移动，因此我只更改 x 坐标。

这是我的解决方案：

    if (longpressGestRec.state == UIGestureRecognizerStateChanged)
    {
        UIView *view = longpressGestRec.view;

        // Location of the touch within the view.
        CGPoint point = [longpressGestRec locationInView:view];

        // Calculate new X position based on the amount the gesture
        // has moved plus the size of the view we want to move.
        CGFloat newXLoc = (item.frame.origin.x + point.x) - (item.frame.size.width / 2);
        [item setFrame:CGRectMake(newXLoc,
                                  item.frame.origin.y,
                                  item.frame.size.width,
                                  item.frame.size.height)];
    }

Answer 5

感谢 Hari Kunwar 提供 Swift 代码，但 longPressAction 函数未正确定义。

这是一个改进版本：

@objc func longPressAction(gesture: UILongPressGestureRecognizer)  {
    if gesture.state == UIGestureRecognizerState.began {
    }
    else if gesture.state == .changed {
        guard let view = gesture.view else {
            return
        }
        let location = gesture.location(in: self.view)
        view.center = CGPoint(x:view.center.x + (location.x - view.center.x),
                                          y:view.center.y + (location.y - view.center.y))
    }
    else if gesture.state == UIGestureRecognizerState.ended{
    }
}