结合长按手势和拖动手势

Question

我正在移动我的观点

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

现在，我希望通过长按拖动来做同样的事情。

任何的想法？

Answer 1

UILongPressGestureRecognizer已经为你做了你想做的事。看看UIGestureRecognizerState酒店。来自documentation：

长按手势是连续的。当指定时间段（minimumPressDuration）按下允许的手指数（numberOfTouchesRequired）并且触摸不超出允许的移动范围（allowableMovement）时，手势开始（UIGestureRecognizerStateBegan）。每当手指移动时，手势识别器转换到改变状态，并且当任何手指被抬起时，手势识别器结束（UIGestureRecognizerStateEnded）。

因此，基本上在调用UILongPressGestureRecognizerselector之后，您将收听UIGestureRecognizerStateBegan，UIGestureRecognizerStateChanged，UIGestureRecognizerStateEnded。在UIGestureRecognizerStateChanged期间继续更改您的视图框架。

- (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;

在我的情况下，我只希望视图水平移动，所以我只是改变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的Swift代码，但是没有正确定义longPressAction函数。

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{
    }
}