UIViewControllerHierarchyInconsistency - 一个视图一次最多只能有一个视图控制器答案

【问题标题】：UIViewControllerHierarchyInconsistency - A view can only be at most with one view controller at a timeUIViewControllerHierarchyInconsistency - 一个视图一次最多只能有一个视图控制器
【发布时间】：2012-09-25 01:42:16
【问题描述】：

我在更新我的一个旧应用程序时遇到问题，这只是因为我更新到 Xcode 4.5 并尝试在 iOS6 上出现以下错误；

*** Terminating app due to uncaught exception 'UIViewControllerHierarchyInconsistency', reason: 'A view can only be associated with at most one view controller at a time! View <MainView: 0x1e818620; frame = (0 0; 320 476); autoresize = RM+BM; layer = <CALayer: 0x1e818750>> is associated with <MainViewController: 0x1e811850>. Clear this association before associating this view with <UIViewController: 0x21149860>.'

* 首先抛出调用栈：（0x377d82a3 0x35ae897f 0x377d81c5 0x38b0dd7b 0x38b0dc6b 0x1dc25 0x38b940ad 0x38b9405f 0x38b9403d 0x38b938f3 0x38b93de9 0x38abc5f9 0x38aa9809 0x38aa9123 0x37c5c5a3 0x37c5c1d3 0x377ad173 0x377ad117 0x377abf99 0x3771eebd 0x3771ed49 0x37c5b2eb 0x38afd301 0x1bf03 0x1bea8） libc++abi.dylib：终止调用抛出异常 [切换到进程9219线程0x2403]

我认为是这里导致了问题；

 mailComposer = [[UIViewController alloc] init];
[mailComposer setView:self];
[mailComposer setModalTransitionStyle: UIModalTransitionStyleCoverVertical];




MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];   picker.mailComposeDelegate = self;

当我单击应该将我带到 MFMail 编写器的按钮时，应用程序崩溃了。

有什么想法吗？

提前致谢

编辑 - 如果我删除前 3 行，应用程序不会崩溃，但是邮件视图不会加载...这是整个代码；

    // The actual mail window call



mailComposer = [[UIViewController alloc] init];
[mailComposer setView:self];
[mailComposer setModalTransitionStyle: UIModalTransitionStyleCoverVertical];




MFMailComposeViewController *picker = [[MFMailComposeViewController alloc] init];   picker.mailComposeDelegate = self;

[picker setSubject:@"Hello How are you"];

    // Fill out the email body text
NSString *pageLink = @"http://www.apple.com"; 
NSString *iTunesLink = @"http://itunes.apple.com/gb/artist/randomer";
NSString *content = @"blah blah"; 


NSString *emailFileName = [NSString stringWithFormat:@"email_.html"];


NSString *emailFilePath = [[[NSBundle mainBundle] resourcePath] stringByAppendingPathComponent: emailFileName];
NSString *body = [NSString stringWithContentsOfFile:emailFilePath encoding:NSUTF8StringEncoding error:nil];


body = [body stringByReplacingOccurrencesOfString:@"//TEXT_PLACEHOLDER//" withString:@"replace here"];
body = [body stringByReplacingOccurrencesOfString:@"//FRIENDNAME_PLACEHOLDER//" withString:pageLink];
body = [body stringByReplacingOccurrencesOfString:@"//ITUNES_PLACEHOLDER//" withString:  iTunesLink];
body = [body stringByReplacingOccurrencesOfString:@"//PASSKEY_PLACEHOLDER//" withString:  yourPassword];
body = [body stringByReplacingOccurrencesOfString:@"//PHONETIC_PLACEHOLDER//" withString:  yourPhoneticPassword];




[picker setMessageBody:body isHTML:YES];    
picker.navigationBar.barStyle = UIBarStyleBlack;    
[mailComposer presentModalViewController:picker animated:YES];
[picker release];

}

//HANDLE THE MAIL EVENTS
////////////////////////

(void)mailComposeController:(MFMailComposeViewController*)controller didFinishWithResult:(MFMailComposeResult)result 错误:(NSError*)error { // 通知用户与接口相关的错误切换（结果） { 案例 MFMailComposeResultCancelled：休息; 案例 MFMailComposeResultSaved：休息; 案例 MFMailComposeResultSent：休息; 案例 MFMailComposeResultFailed：休息;
```
default:
{
    UIAlertView *alert = [[UIAlertView alloc] initWithTitle:@"Email" message:@"Sending Failed - Unknown Error :-("
                                                   delegate:self cancelButtonTitle:@"OK" otherButtonTitles: nil];
    [alert show];
    [alert release];
}

    break;
```
} [mailComposerdismissModalViewControllerAnimated:YES]; //[mailComposer.view.superview removeFromSuperview]; }

【问题讨论】：

这条线是做什么的？ self 这里是什么？ [mailComposer setView:self];
你只需要最后一行。前 3 行是什么？
有什么想法吗？在这里挣扎:(
好吧，找到了一个临时的解决方法...返回并在 Xcode 4.2.1 中编译！在找到修复之前忘记 4.5！

标签： ios xcode ios6

【解决方案1】：

让邮件撰写视图控制器显示的主要内容是使用当前活动的 UIViewController 来显示它。你没有分享足够多的代码让我明白这一点，但如果 self 在这种情况下是 UIViewController，你需要这样做：

[self presentViewController:picker animated: YES completion:nil];

如果 self 不是 UIViewController，请将上面代码中的 self 替换为引用当前 UIViewController 的变量。

【讨论】：