ios - 在启动时以编程方式为 5 个选项卡栏项目设置选项卡栏标题，其中 4 个嵌入在导航 Controller 中，1 个不是。 objective-c

Question

如何在 Startup 或 AppDelegates 中设置标签栏标题。我有 5 个 Tab Bar Item，其中 4 个嵌入在 Navigation Controller 中，1 个没有，只是一个 tab bar item。请看下图

更新调用方法的VC

#import "AppDelegate.h"

@interface ProfileChgLang (){

    AppDelegate *appDelegate;
    NSString *sLanguage;
}

- (IBAction)btnChinese:(id)sender {

    NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];
    [defaults setObject:@"CN" forKey:@"txtLanguage"];

    [(AppDelegate*)[UIApplication sharedApplication].delegate setupTabBar];

    //UIStoryboard *storyboard = [UIStoryboard storyboardWithName:@"Main" bundle:nil];
    //==== Is the following correct? ===== 
    UITabBarController * tabBarController = (UITabBarController*)[[[UIApplication sharedApplication] keyWindow] rootViewController];
    [self presentViewController:tabBarController animated:YES completion:nil];
 }
    //====================================

应用委托(delegate)更新

 - (void)setupTabBar {
    //===Should be this 
    UITabBarController * tabBarController = (UITabBarController*)[self.window rootViewController];
    //===Or this 
    UITabBarController * tabBarController = (UITabBarController*)[[[UIApplication sharedApplication] keyWindow] rootViewController];

    if(tabBarController != nil) {
        ((UIViewController*)[tabBarController.viewControllers objectAtIndex:1]).tabBarItem.title = @"Your desired Title";
     }

Answer 1

任何 UIViewController 都有这个属性 tabBarItem 因为它是 UIViewController 的扩展所以你只需要获取你的 viewController 并设置他的 tabBarItem.title property = "your desiredTitle"

更新

Objective-C 代码

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
    [self setupTabBar];
    // Override point for customization after application launch.
    return YES;
}

- (void)setupTabBar {
    UITabBarController * tabBarController = (UITabBarController*)[self.window rootViewController];
    if(tabBarController != nil) {
        ((UIViewController*)[tabBarController.viewControllers objectAtIndex:3]).tabBarItem.title = @"YourDesiredTitle";
    }
}

Swift 代码

func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplicationLaunchOptionsKey: Any]?) -> Bool {

        //Whatever you have here
        self.setupTabBar()

        return true
    }

func setupTabBar() {

    if let tabBarController = self.window?.rootViewController as? UITabBarController {
       if let navigationsControllers = tabBarController.viewControllers as? [UIViewController] {
   navigationsControllers[3].tabBarItem.title = "YourTitle"
       }
   }
}

更新#2

如果你想从代码中的任何地方调用这个方法，你必须

1. 将您的 AppDelegate.h 导入您要使用它的 .m 中
2. 将此方法添加到您的 AppDelegate.h 中以公开此方法
3. 像这样调用这个方法:

代码

   [(AppDelegate*)[UIApplication sharedApplication].delegate setupTabBar];