呈现模态视图偶尔会隐藏导航栏 [英] Presenting modal view occasionally hides the navigation bar

问题描述

我现在遇到过两次。

有时使用下面的代码：

  [self.navigationController presentModalViewController：aViewController animated：YES]; 
  

显示视图，但导航栏随后隐藏。

我可以写：

  [self.navigationController setNavigationBarHidden：NO]; 
  

到我心中的内容，无处不在，我可以想到没有效果。

$ b $

>解决方案

不，我也碰到了这个。问题是，当您提供一个模式视图控制器与基于UIViewController的类，它不会将调用导航控制器的导航栏扩展到模态。模态视图覆盖整个屏幕。我最后做的是解决问题是创建一个UINavigationController，并推送基于UIViewController的类，然后做presentModalViewController到导航控制器的实例。

like：

  UIViewController * vc = [[UIViewController alloc] init]; 
 UINavigationController * cntrol = [[UINavigationController alloc] initWithRootViewController：vc]; 
 [self presentModalViewController：cntrol animated：YES]; 
 [cntrol release]; 
  

这让我在顶部有一个导航栏。

我不知道这是否会帮助你的特定情况下，唯一的其他事情，我建议是用UIAnimation复制模态的行为，停止44px低于手机的顶部。这将保持原始导航栏显示。

I've come across this twice now.

Sometimes using the following line of code:

[self.navigationController presentModalViewController:aViewController animated:YES];

displays the view, but the navigation bar is then hidden.

I can write:

[self.navigationController setNavigationBarHidden:NO];

to my hearts content, everywhere I can think of with no effect.

Has anyone ran into this?

Am I doing something silly?

解决方案

No, I ran into this as well. The problem is that when you present a modal view controller with a UIViewController based class, it does not extend the calling navigation controller's nav bar onto the modal. The modal view covers the entire screen. What I ended up doing to solve the problem was to create a UINavigationController and push the UIViewController based class onto it, and then do presentModalViewController to the navigation controller's instance.

like:

UIViewController *vc = [[UIViewController alloc] init];
UINavigationController *cntrol = [[UINavigationController alloc] initWithRootViewController:vc];
[self presentModalViewController:cntrol animated:YES];
[cntrol release];

That allowed me to have a nav bar at the top.

I am not sure if that will help in your particular case, the only other thing I would suggest is to replicate the behavior of the modal with a UIAnimation that stops 44px below the top of the phone. That would keep the original navigation bar visible.

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