Question

我在UILabel中有一个subview，panGesture上有一个pinchGesture和UILabel。截至目前，我可以移动UILabel横过所有视图。我希望此UILabel留在subView区域内。我怎么做到这一点？

- (void)handlePanGesture:(UIPanGestureRecognizer *)panGesture {
CGPoint translation = [panGesture translationInView:panGesture.view.superview];

if (UIGestureRecognizerStateBegan == panGesture.state ||UIGestureRecognizerStateChanged == panGesture.state) {
    panGesture.view.center = CGPointMake(panGesture.view.center.x + translation.x,
                                         panGesture.view.center.y + translation.y);
    [panGesture setTranslation:CGPointZero inView:self.view];
 }
}

在这一行中，

CGPoint translation = [panGesture translationInView:panGesture.view.superview];

它将它设置为superView，我正在尝试将其设置为我的subView，但我似乎无法弄明白。

Answer 1

这是我的代码，用于处理可拖动按钮并将其限制在主视图边界我希望这段代码可以帮到你

 CGPoint translation = [recognizer translationInView:self.view];
    CGRect recognizerFrame = recognizer.view.frame;
    recognizerFrame.origin.x += translation.x;
    recognizerFrame.origin.y += translation.y;

    // Check if UIImageView is completely inside its superView
    if (CGRectContainsRect(self.view.bounds, recognizerFrame)) {
        recognizer.view.frame = recognizerFrame;
    }
    // Else check if UIImageView is vertically and/or horizontally outside of its
    // superView. If yes, then set UImageView's frame accordingly.
    // This is required so that when user pans rapidly then it provides smooth translation.
    else {
        // Check vertically
        if (recognizerFrame.origin.y < self.view.bounds.origin.y) {
            recognizerFrame.origin.y = 0;
        }
        else if (recognizerFrame.origin.y + recognizerFrame.size.height > self.view.bounds.size.height) {
            recognizerFrame.origin.y = self.view.bounds.size.height - recognizerFrame.size.height;
        }

        // Check horizantally
        if (recognizerFrame.origin.x < self.view.bounds.origin.x) {
            recognizerFrame.origin.x = 0;
        }
        else if (recognizerFrame.origin.x + recognizerFrame.size.width > self.view.bounds.size.width) {
            recognizerFrame.origin.x = self.view.bounds.size.width - recognizerFrame.size.width;
        }
    }

    // Reset translation so that on next pan recognition
    // we get correct translation value
    [recognizer setTranslation:CGPointZero inView:self.view];

为UIPangesture添加边界

1 个答案: