Question

我正在尝试从另一个（BasicSearchController）加载一个导航控制器（ViewController）。在Storyboard中，我创建了2个导航控制器，它们不是由segue链接，而是单独的Nagivation控制器。每个都分别链接到ViewController和BasicSearchController，每个视图控制器在导航栏中都有自己的标题文本。

在ViewController.m我的应用中，我有一个导航栏项目，使用此代码显示：

searchButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"search-icon.png"] landscapeImagePhone:[UIImage imageNamed:@"search-icon.png"] style:UIBarButtonItemStylePlain target:self action:@selector(presentSearch)];

按下按钮时，会调用此方法：

- (void) presentSearch {
    NSLog(@"Search presented!");

    [self performSelector:@selector(pushBasicSearchController) withObject:self afterDelay:0.0];
    }

最后，选择器运行此代码：

- (IBAction)pushBasicSearchController {
BasicSearchController *basicController = [[BasicSearchController alloc] init];

[self presentViewController:basicController animated:YES completion:NULL];
}

在BasicSearchController中，然后呈现，我有以下代码来生成用户界面：

- (void) createInterface {

screenRect = [[UIScreen mainScreen] bounds];
screenWidth = screenRect.size.width;
screenHeight = screenRect.size.height;

UIImage *navBackgroundImage = [UIImage imageNamed:@"bar.png"];
[[UINavigationBar appearance] setBackgroundImage:navBackgroundImage forBarMetrics:UIBarMetricsDefault];

backgroundView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"background1.png"]];
[backgroundView setFrame:CGRectMake(0, 0, screenWidth, screenHeight)];
[backgroundView setContentMode:UIViewContentModeScaleToFill];
[[self view] addSubview:backgroundView];
[[self view] sendSubviewToBack:backgroundView];

underBarGradient = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"gradient-under-bar.png"]];
[underBarGradient setFrame:CGRectMake(0, 64, screenWidth, 3)];
[underBarGradient setContentMode:UIViewContentModeScaleToFill];
[underBarGradient setAlpha:0.5f];
[[self view] addSubview:underBarGradient];
[[self view] bringSubviewToFront:underBarGradient];

menuButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"menu.png"] landscapeImagePhone:[UIImage imageNamed:@"menu.png"] style:UIBarButtonItemStyleDone target:self action:@selector(presentMenu)];

navigationItemMain.leftBarButtonItem = menuButton;

searchButton = [[UIBarButtonItem alloc] initWithImage:[UIImage imageNamed:@"search-icon.png"] landscapeImagePhone:[UIImage imageNamed:@"search-icon.png"] style:UIBarButtonItemStylePlain target:self action:@selector(presentSearch)];

navigationItemMain.rightBarButtonItem = searchButton;

NSLog(@"UI created!");

}

underBarGradient和backGroundView已正确显示。但是，NagivationBar及其标题文本不可见，导航栏项目也缺失。

回到ViewController，我在AppDelegate.m中使用以下代码来自定义导航栏：

I have modified `ViewController`'s navigation bar's appearance using the following code, which is found in `AppDelegate.m`:

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
// Override point for customization after application launch.
[[UINavigationBar appearance] setBackgroundImage:[UIImage imageNamed:@"bar.png"] forBarMetrics:UIBarMetricsDefault];
NSShadow* shadow = [NSShadow new];
shadow.shadowOffset = CGSizeMake(1.0f, 1.0f);
shadow.shadowColor = [UIColor clearColor];
[[UINavigationBar appearance] setTitleTextAttributes: @{
                                                        NSForegroundColorAttributeName: [UIColor whiteColor],
                                                        NSFontAttributeName: [UIFont fontWithName:@"Aliquam" size:20.0f],
                                                        NSShadowAttributeName: shadow
                                                        }];
return YES;
}

但是，虽然这适用于ViewController的导航栏，但此代码不会修改BasicSearchController的栏。

我的疑问是：

如何使用AppDelegate中使用的代码自定义BasicSearchController的导航栏？
如何让导航栏项目显示在BasicSearchController？

Answer 1

这就是问题所在：

- (IBAction)pushBasicSearchController {
    BasicSearchController *basicController = [[BasicSearchController alloc] init];

    [self presentViewController:basicController animated:YES completion:NULL];
}

你没有推动你的表现。您需要使用以下命令推送视图控制器：

[self.navigationController pushViewController: basicController animated:YES];

这将解决缺少的NavigationBar。

用于自定义NavigationBar

最好在视图控制器.m文件中自定义单个NavigationBar，最好是viewWillAppear方法。你没有指定你想要的可定制性，所以我会留下你的想象力。

Answer 2

我已经解决了:)我改变了

<img src ="https://bb9.canyons.edu/bbcswebdav/pid-692768-dt-content-rid-9288981_1/courses/2015SU-CMPSCI190-16424/tick.gif" title="insert original image title here" onclick="this.title='My New Title';"/>

到

navigationItemMain.rightBarButtonItem = searchButton;

在目标视图控制器（basicSearchController）中。我也使用了代码

self.navigationItem.rightBarButtonItem = searchButton;

在SASmith提供的代码中按下控制器后立即执行，该代码隐藏了后退按钮，并在导航栏中添加了标题。您可以在目标视图控制器中使用此代码，但它会使按钮弹出，而不是直接显示。

感谢您的帮助！

在以编程方式呈现ViewController时，不会加载NavigationBar

2 个答案: