ios 在演示或关闭正在进行时尝试从视图控制器中关闭
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Attempt to dismiss from view controller while a presentation or dismiss is in progress
提问by Harish
I have TWO UIViewControllerclasses, where in FirstClassi have an UIButtonfor Login, when user taps on button, i will display SecondClass... For that i have done,
我有两个UIViewController类，其中FirstClass有一个UIButtonfor Login，当用户点击按钮时，我将显示SecondClass......为此我已经完成了，
SecondClass *index = [[SecondClass alloc] init];
[self presentModalViewController:index animated:YES];
In SecondClass i have a logoutbutton, which will redirect to FirstClass, for that i have done,
在 SecondClass 我有一个注销按钮，它将重定向到FirstClass，因为我已经完成了，
[self dismissModalViewControllerAnimated:YES];
When i press Logout button in SecondClass, i get the warning msg
当我在 SecondClass 中按下注销按钮时，我收到警告消息
**Attempt to dismiss from view controller <FirstClass: 0e39w88e160> while a presentation or dismiss is in progress!**
What is the problem here..
这里有什么问题..
回答by Kevin Zych
Added both iOS 6 and pre-iOS 6 answers:
添加了 iOS 6 和 iOS 6 之前的答案：
iOS 5.0 and later
iOS 5.0 及更高版本
When you logout, add this check before dismissing:
当您注销时，在解除之前添加此检查：
if (![self.presentedViewController isBeingDismissed])
{
[self dismissModalViewControllerAnimated:YES completion:nil];
}
iOS 4.X and less
iOS 4.X 及以下
Add this check before dismissing:
在解雇之前添加此检查：
if (![[self modalViewController] isBeingDismissed])
{
[self dismissModalViewControllerAnimated:YES];
}
回答by Vishal
Call these lines where you logout & then check:
在您注销的地方调用这些行，然后检查：
if (![[self modalViewController] isBeingDismissed])
{
[self dismissModalViewControllerAnimated:YES];
}
回答by Tom Susel
There are many things that may cause this, here are some options:
导致这种情况的原因有很多，这里有一些选择：
- You forgot to call super on one of the ViewController methods such as viewWillAppear, viewWillAppear etc. Consult the UIViewController documentation to see when you have to call super.
- The dismissModalViewControllerAnimated: method is being called more than once, this can happen if you added a target to the UIButton more than once.
- 您忘记在 ViewWillAppear、viewWillAppear 等 ViewController 方法之一上调用 super。请参阅 UIViewController 文档以了解何时必须调用 super。
- DismissModalViewControllerAnimated: 方法被多次调用，如果您多次向 UIButton 添加目标，就会发生这种情况。
To get better understanding of the problem please paste the code of both view controllers in its entirety.
为了更好地理解问题，请完整粘贴两个视图控制器的代码。
