ios - 从视图控制器呈现导航视图 - IOS 7

Question

当我需要从视图控制器显示导航控制器时出现错误，如下所示：

“警告：尝试呈现不在窗口层次结构中的视图！”

代码如下：

UIStoryboard* storyboard = [UIStoryboard storyboardWithName:@"NavMain" bundle:nil];
UINavigationController * mainViewController = [storyboard instantiateInitialViewController];
mainViewController.modalPresentationStyle = UIModalPresentationFormSheet;
[self presentViewController:mainViewController animated:YES completion:NO];

如何修复错误或在实现情节提要时出现任何错误？我使用两个故事板从main.storyboard到NavMain.storyboard

Answer 1

The error means that self's view hasn't loaded yet. You want to call this code after the view has loaded. So put it in:

    -(void)viewDidAppear:(BOOL)animated;