Ios 如何通过平移手势限制可移动视图

我有一个

UIImageView

，可以通过平移手势移动

UIPanGestureRecognizer *pan = [[UIPanGestureRecognizer alloc] initWithTarget:self action:@selector(handlePan:)];
[self.photoMask addGestureRecognizer:pan];

我想限制屏幕上可以移动的区域。我不希望用户能够将视图向右拖动到屏幕的一侧，而是希望通过某种方式限制它。我该怎么做

另外，旋转时如何处理

编辑--

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这是我目前处理平底锅的方法。我需要做的是继续按中心点移动imageview，并限制其在靠近屏幕边缘时的移动，例如50。

我不确定我在这里是否过于简单，但我认为可以通过使用if子句来实现这一点

-(void)handlePan:(UIPanGestureRecognizer*)gesture {

    UIImageView *viewToDrag = gesture.view; // this is the view you want to move

    CGPoint translation = [gesture translationInView:viewToDrag.superview]; // get the movement delta

    CGRect movedFrame = CGRectOffset(viewToDrag.frame, translation.x, translation.y); // this is the new (moved) frame

    // Now this is the critical part because I don't know if your "margin"
    // is a CGRect or maybe some int values, the important thing here is
    // to compare if the "movedFrame" values are in the allowed movement area

    // Assuming that your margin is a CGRect you could do the following:
    if (CGRectContainsRect(yourPermissibleMargin, movedFrame)) {
        CGPoint newCenter = CGPointMake(CGRectGetMidX(movedFrame), CGRectGetMidY(movedFrame));
        viewToDrag.center = newCenter; // Move your view
    }

    // -OR-

    // If you have your margins as int values you could do the following:
    if ( (movedFrame.origin.x + movedFrame.size.width) < 50) {
        CGPoint newCenter = CGPointMake(CGRectGetMidX(movedFrame), CGRectGetMidY(movedFrame));
        viewToDrag.center = newCenter; // Move your view
    }
}

-（void）手持面板：（UIPangestureRecognitor*）手势{
UIImageView*viewToDrag=SISTER.view；//这是要移动的视图
CGPoint translation=[手势转换视图：viewToDrag.superview]；//获取移动增量
CGRect movedFrame=CGRectOffset（viewToDrag.frame，translation.x，translation.y）；//这是新的（移动的）帧
//现在这是关键部分，因为我不知道你的“利润”
//是一个CGRect或者一些int值，这里重要的是
//比较“movedFrame”值是否在允许的移动区域
//假设您的保证金是CGRect，您可以执行以下操作：
if（CGRectContainsRect（您的许可证argn，movedFrame））{
CGPoint newCenter=CGPointMake（CGRectGetMidX（movedFrame），CGRectGetMidY（movedFrame））；
viewToDrag.center=newCenter；//移动视图
}
//-或-
//如果将边距设置为int值，则可以执行以下操作：
if（（movedFrame.origin.x+movedFrame.size.width）<50）{
CGPoint newCenter=CGPointMake（CGRectGetMidX（movedFrame），CGRectGetMidY（movedFrame））；
viewToDrag.center=newCenter；//移动视图
}
}

您可能需要对其进行调整以满足您的特定需求

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希望这有帮助

一个可能的解决方案是使用handlePan方法，检查屏幕上点的位置，并且仅在您希望限制的范围内提交更改

例如

-(void) handlePan:(UIGestureRecognizer*)panGes{

    CGPoint point = [panGes locationInView:self.view];

    //Only allow movement up to within 100 pixels of the right bound of the screen
    if (point.x < [UIScreen mainScreen].bounds.size.width - 100) {

        CGRect newframe = CGRectMake(point.x, point.y, theImageView.frame.size.width, theImageView.frame.size.height);

        theImageView.frame = newframe;

    }

}

---

检查该点是否在您想要的范围内，如果是，请将图像视图框的中心设置为该点。

以下是Swift 4-

- (void)dragAction:(UIPanGestureRecognizer *)gesture{
     UILabel *label = (UILabel *)gesture.view;
     CGPoint translation = [gesture translationInView:label];
     if (CGRectContainsPoint(label.frame, [gesture locationInView:label] )) {
         label.center = CGPointMake(label.center.x,
                                label.center.y);
        [gesture setTranslation:CGPointZero inView:label];
   }
   else{
       label.center = CGPointMake(label.center.x,
                                label.center.y + translation.y);
        [gesture setTranslation:CGPointZero inView:label];
   }
}

将视图的移动限制为superview

@objc func handlePan(_ gestureRecognizer: UIPanGestureRecognizer)
{
    // Allows smooth movement of stickers.
    if gestureRecognizer.state == .began || gestureRecognizer.state == .changed
    {
        let point = gestureRecognizer.location(in: self.superview)
        if let superview = self.superview
        {
            let restrictByPoint : CGFloat = 30.0
            let superBounds = CGRect(x: superview.bounds.origin.x + restrictByPoint, y: superview.bounds.origin.y + restrictByPoint, width: superview.bounds.size.width - 2*restrictByPoint, height: superview.bounds.size.height - 2*restrictByPoint)
            if (superBounds.contains(point))
            {
                let translation = gestureRecognizer.translation(in: self.superview)
                gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
                gestureRecognizer.setTranslation(CGPoint.zero, in: self.superview)
            }
        }
    }
}

---

如果您想对其进行更多控制，请将restrictByPoint值与移动视图的框架相匹配。

谢谢，我已为我的问题添加了一个编辑。目前，我从中心点移动视图。这样，我移动的图像视图（中间有一个圆）看起来像是圆在移动。。。我正在尝试更新您的答案，以纳入此中心点，但不确定如何更新？我想继续提出中间观点（然后检查此中间点是否在屏幕的限制区域内。例如，整个屏幕周围有50个边距？如果您尝试快速拖动视图，则此if条件将中断。谢谢，我已对我的问题添加了一个编辑。目前，我从中心点移动视图。这样，我移动的图像视图（中间有一个圆）使它看起来像是在移动…我正在尝试更新你的答案以包含这个中心点，但不确定如何添加？我希望继续移动视图的中间点（然后检查该中点是否在屏幕的限制区域内。例如，整个屏幕周围有50个边距？使用MAX（minFloat，MIN（x，maxFloat））

- (void)dragAction:(UIPanGestureRecognizer *)gesture{
     UILabel *label = (UILabel *)gesture.view;
     CGPoint translation = [gesture translationInView:label];
     if (CGRectContainsPoint(label.frame, [gesture locationInView:label] )) {
         label.center = CGPointMake(label.center.x,
                                label.center.y);
        [gesture setTranslation:CGPointZero inView:label];
   }
   else{
       label.center = CGPointMake(label.center.x,
                                label.center.y + translation.y);
        [gesture setTranslation:CGPointZero inView:label];
   }
}

@objc func handlePan(_ gestureRecognizer: UIPanGestureRecognizer)
{
    // Allows smooth movement of stickers.
    if gestureRecognizer.state == .began || gestureRecognizer.state == .changed
    {
        let point = gestureRecognizer.location(in: self.superview)
        if let superview = self.superview
        {
            let restrictByPoint : CGFloat = 30.0
            let superBounds = CGRect(x: superview.bounds.origin.x + restrictByPoint, y: superview.bounds.origin.y + restrictByPoint, width: superview.bounds.size.width - 2*restrictByPoint, height: superview.bounds.size.height - 2*restrictByPoint)
            if (superBounds.contains(point))
            {
                let translation = gestureRecognizer.translation(in: self.superview)
                gestureRecognizer.view!.center = CGPoint(x: gestureRecognizer.view!.center.x + translation.x, y: gestureRecognizer.view!.center.y + translation.y)
                gestureRecognizer.setTranslation(CGPoint.zero, in: self.superview)
            }
        }
    }
}