从已呈现的ViewController推送控制器时导航栏不显示

我通过UINavigationController以模态方式呈现了ViewController A，并隐藏了其导航栏。但推送ViewController B时，即使在B中设置self.navigationController?.setNavigationBarHidden(false, animated: false)也无法让导航栏显示，相关代码及背景信息如下：

呈现ViewController A的Objective-C代码 #

AppDelegate* delegate = [AppDelegate applicationDelegate];
UIStoryboard *story = [UIStoryboard storyboardWithName:STORYBOARD_MAIN bundle:nil];
SelectionViewController *tutorial = [story instantiateViewControllerWithIdentifier:@"SelectionViewController"];
tutorial.providesPresentationContextTransitionStyle = YES;
tutorial.definesPresentationContext = YES;
[tutorial setModalPresentationStyle:UIModalPresentationOverCurrentContext];
tutorial.delegate = self;

UINavigationController* navController = [[UINavigationController alloc] initWithRootViewController:tutorial];
navController.modalPresentationStyle = UIModalPresentationFullScreen;
[navController.navigationBar setHidden:YES];
navController.providesPresentationContextTransitionStyle = YES;
navController.definesPresentationContext = YES;
[navController setModalPresentationStyle:UIModalPresentationOverCurrentContext];
[delegate.tabBarController presentViewController:navController animated:YES completion:NULL];

推送ViewController B的代码（Objective-C调用Swift控制器） #

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"AppDetail" bundle:nil];
DetailViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"DetailViewController"];
[self.navigationController pushViewController:vc animated:YES];
[[self navigationController] setNavigationBarHidden:NO];

补充信息 #

• ViewController A基于Objective-C编写，ViewController B基于Swift编写
• 两个控制器分别位于不同的Storyboard中

解决方法 #

1. 用导航控制器的官方方法管理导航栏状态 #

你当前直接修改navController.navigationBar.hidden属性，这会绕过UINavigationController的内部状态管理逻辑，导致后续推送控制器时状态无法同步更新。

将呈现导航控制器时的隐藏代码替换为：

// 替换 [navController.navigationBar setHidden:YES];
[navController setNavigationBarHidden:YES animated:NO];

2. 调整推送B时的导航栏设置时机 #

可以选择两种方式确保导航栏正确显示：

方式一：在A中推送前/后设置

调整推送代码的顺序，先设置导航栏显示再推送（或配合动画同步执行）：

UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"AppDetail" bundle:nil];
DetailViewController *vc = [storyboard instantiateViewControllerWithIdentifier:@"DetailViewController"];
// 先设置导航栏显示，再推送，保持动画一致
[self.navigationController setNavigationBarHidden:NO animated:YES];
[self.navigationController pushViewController:vc animated:YES];

方式二：在B的生命周期方法中设置

在B的Swift代码中，重写viewWillAppear方法强制显示导航栏：

override func viewWillAppear(_ animated: Bool) {
    super.viewWillAppear(animated)
    self.navigationController?.setNavigationBarHidden(false, animated: animated)
}

如果需要返回A时重新隐藏导航栏，可以在viewWillDisappear中恢复：

override func viewWillDisappear(_ animated: Bool) {
    super.viewWillDisappear(animated)
    self.navigationController?.setNavigationBarHidden(true, animated: animated)
}

3. 清理冗余的模态样式设置 #

你同时给ViewController A和它所在的导航控制器设置了UIModalPresentationOverCurrentContext，这会导致上下文冲突。建议只保留导航控制器的模态样式设置，移除A的相关代码：

// 移除以下三行冗余代码
// tutorial.providesPresentationContextTransitionStyle = YES;
// tutorial.definesPresentationContext = YES;
// [tutorial setModalPresentationStyle:UIModalPresentationOverCurrentContext];

内容的提问来源于stack exchange，提问作者Rahul Vyas