UIPanGestureRecognizer有时无法在iOS 7上运行 [英] UIPanGestureRecognizer sometimes not working on iOS 7

问题描述

我收到来自iOS 7用户的间歇性报告，称 UIPanGestureRecognizer 每隔一段时间停止处理某些视图。他们应该能够向右/向左滑动视图，但它只是因为某种未知原因而中断并且不起作用。强制退出应用程序并重新启动它可以解决问题。

I'm getting intermittent reports from users on iOS 7 saying that the UIPanGestureRecognizer stops working on certain views every once in a while. They're supposed to be able to swipe a view to the right/left, but it just breaks and doesn't work for some unknown reason. Force quitting the app and relaunching it fixes the problem.

这个问题在iOS 6上从未发生过。除了 gestureRecognizerShouldBegin之外，我没有任何禁用手势识别器的代码委托强制手势仅识别水平平底锅：

This problem never happened on iOS 6. And I don't have any code that disables the gesture recognizer at any time besides the gestureRecognizerShouldBegin delegate that forces the gesture to only recognize horizontal pans:

- (BOOL)gestureRecognizerShouldBegin:(UIPanGestureRecognizer *)gestureRecognizer {

    if ([gestureRecognizer isMemberOfClass:[UIPanGestureRecognizer class]]) { 

        CGPoint translation = [gestureRecognizer translationInView:[self superview]];

        if (fabsf(translation.x) > fabsf(translation.y)) {

            if (translation.x > 0)
                return YES;
        }
    }
    return NO;
}

UIPanGestureRecognizer （或只是简单的 UIGestureRecognizer ）？

推荐答案

我想我终于解决了这个问题。显然，iOS 7处理子视图中的手势与iOS 6及更早版本中的手势不同。为了解决这个问题，Apple实施了一个新的委托：

I think I finally solved this issue. Apparently iOS 7 handles gestures in subviews differently than it did in iOS 6 and earlier. To handle this, Apple implemented a new delegate:

(BOOL)gestureRecognizer:(UIGestureRecognizer *)gestureRecognizer shouldBeRequiredToFailByGestureRecognizer:(UIGestureRecognizer *)otherGestureRecognizer

如果您返回YES，那么应该让您的手势识别器工作。我已经实现了它并且到目前为止没有任何问题（尽管这是一个罕见的错误，我永远无法可靠地重现，所以它可能还没有复发）。

If you return YES, that should get your gesture recognizer to work. I've implemented it and haven't had any issues so far (though admittedly this was a rare bug that I could never reliably reproduce, so it's possible that it just hasn't recurred yet).

有关详细信息，请参阅
https://stackoverflow.com/a/19892166/1593765 。

For more information, see https://stackoverflow.com/a/19892166/1593765.

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