popViewController Animated 的断断续续的动画：来自警报 View:didDismissWithButtonIndex:

Question

当在 UIalertView 委托方法 alertView:didDismissWithButtonIndex: 中完成时，我遇到了方法 popViewControllerAnimated: 中的动画问题。它不稳定且快速（使用 Xcode 7.3.1）。谁能明白为什么？

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex != alertView.cancelButtonIndex)
    {
        // animation of popViewControllerAnimated: is not working correctly
        [self.navigationController popViewControllerAnimated:YES];
    }
}

奇怪的是这段代码没有问题：

- (void)alertView:(UIAlertView *)alertView didDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex != alertView.cancelButtonIndex)
    {
        // code is running om main thread
        if ([[NSThread currentThread]isMainThread])  {
            // still - by using GCD and go to main thread, the animation works!!
            dispatch_async(dispatch_get_main_queue(), ^{
                [self.navigationController popViewControllerAnimated:YES];
            });
        }
    }
}

还有这个：

- (void)alertView:(UIAlertView *)alertView clickedButtonAtIndex:(NSInteger)buttonIndex {

    if(buttonIndex != alertView.cancelButtonIndex)
    {
        // no problem with animation when done in alertView:clickedButtonAtIndex:
        [self.navigationController popViewControllerAnimated:YES];
    }
}

我知道UIAlertView 已经被弃用了一段时间，是不是因为这个？自 2012 年以来，此代码在应用程序中一直未触及，最近开始表现得很奇怪。

Answer 1

您可以尝试使用willDismissWithButtonIndex 而不是didDismissWithButtonIndex

- (void)alertView:(UIAlertView *)alertView willDismissWithButtonIndex:(NSInteger)buttonIndex
{
    if (buttonIndex != alertView.cancelButtonIndex)
    {
        [self.navigationController popViewControllerAnimated:YES];
    }
}

对我来说这项工作还可以！希望对你有所帮助