ios tabBarControl、navigationcontroller 标题和按钮编辑

Question

我一直在我的应用程序中使用标准的 TabBarController 和顶部 NavigationBar。 tabBar 在 appDelegate 中加载，初始化 navigationBar 以使用图像而不是中心标题，这对于所有四个 tabBar View 都存在。有时我会将一个新 View 推送到 View Controller 上，并且效果很好。

我想要做的是能够在 4 个 tabBar View Controller 打开时更改它们中的每一个的 NavigationBar。我在做这件事时遇到了麻烦。我的初始 navigationBar 有一个图像，加载在 appDelegate 中。我的问题是:

• 每个 viewController 通常应该根据需要在各自的 viewWillAppear 方法中从头开始创建一个新的 navigationBar 吗？
• 应该编辑什么 navigationController 和 navigationBar——始终是 appDelegate 的 navigationController、tabBarController.navigationController，还是每个 View 中的 self.navigationController？ (通常，大多数编辑对我来说都不起作用，不会导致任何更改)
• 如果我用 imageView 覆盖标准标题(通常是 tabBar 当前 View 的标题)，并希望另一个 tabBar View 使用标准标题，我应该如何删除 titleView 图像并重置回文本？反之亦然，取决于 View ？这就是我真正想要完成但未成功的事情。

我想我正在寻找管理每个 View 的导航栏并根据 tabBarItem 更改它的标准做法。

// in appDelegate
- (void)initNav {
    self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.delegate = self;
    self.tabBarController.navigationController.view.backgroundColor = [UIColor whiteColor];

    self.tabBarController.viewControllers = [NSArray arrayWithObjects:self.firstViewController,
                                             self.secondViewController,
                                             self.thirdViewController,
                                             self.forthViewController,
                                             nil];


    [self.window addSubview:self.tabBarController.view];
    self.navigationController = [[UINavigationController alloc] initWithRootViewController:self.tabBarController];
    self.navigationController.navigationBarHidden = NO;

    // customize background color of nav bar to "blue"ish color
    self.navigationController.navigationBar.backgroundColor = [UIColor colorWithHexString:@"00A3E1"];
    self.navigationController.navigationBar.tintColor = [UIColor colorWithHexString:@"00A3E1"];
    self.navigationController.navigationBar.barTintColor = [UIColor colorWithHexString:@"00A3E1"];

    [self createNavs];
}

// also in appDelegate
- (void)createNavs {
    // white text when present
    NSDictionary *attributes = [NSDictionary dictionaryWithObjectsAndKeys:
                                [UIColor whiteColor],
                                UITextAttributeTextColor,
                                [UIColor clearColor],
                                UITextAttributeTextShadowColor, nil];

    [[UIBarButtonItem appearance] setTitleTextAttributes: attributes
                                                forState: UIControlStateNormal];


    AppDelegate *delegateRef = (AppDelegate*)[[UIApplication sharedApplication] delegate];

    [self.navigationController.navigationBar setTranslucent:NO];

    // setup left button (currently unused -- no left button)
    /*
    /*
    UIButton *button =  [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:[UIImage imageNamed:@"glyphicons_049_star.png"] forState:UIControlStateNormal];
    [button addTarget:self action:@selector(starClick:) forControlEvents:UIControlEventTouchDown];
    [button setFrame:CGRectMake(0, 0, 25, 25)];
    self.navigationController.navigationBar.topItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:button];
    */

    // setup logo in center
    self.tabBarController.navigationItem.titleView = [[UIImageView alloc] initWithImage:[UIImage imageNamed:@"synced_top_logo.png"]];

    // setup right button (currently unused -- no right button)
    /*
    UIBarButtonItem *rightButton = [[UIBarButtonItem alloc] init];
    rightButton.title = @"edit";
    [rightButton setTarget:self ];
    [rightButton setAction:@selector(editClick:)];
    self.navigationController.navigationBar.topItem.rightBarButtonItem = rightButton;
    */

    [[self navigationController] setNavigationBarHidden:NO animated:YES];
    [[delegateRef navigationController] setNavigationBarHidden:NO animated:YES];
}

编辑:这是下面发布的解决方案的简化版本，很有帮助，并允许进行所需的自定义。每个 View Controller 独立于此自定义其导航栏。可能从一开始就应该这样做。

tabBarController.viewControllers = [NSArray arrayWithObjects:[[UINavigationController alloc] initWithRootViewController:self.firstViewController], 
                                         [[UINavigationController alloc] initWithRootViewController:self.secondViewController],
                                         [[UINavigationController alloc] initWithRootViewController:self.thirdViewController],
                                         [[UINavigationController alloc] initWithRootViewController:self.forthViewController],
                                         nil];

Answer 1

这可能是您需要的:

- (void)initTabbar {

    self.tabBarController = [[UITabBarController alloc] init];
    self.tabBarController.delegate = self;

    /*
     You want each of your UIViewControllers to be wrapped in a UINavigationController. Then put each of those UINavigationControllers in a UITabBarController
    */

    //You don't need to hang on to this becuase the proceeding UINavigationController will handle it
    FirstViewController *firstViewController = [[FirstViewController alloc] ...];

    //You'll need to declare this in your header
    self.firstNavigationController = [[UINavigationController alloc] initWithRootViewController:firstViewController];


    //Second view allocation
    SecondViewController *secondViewController = [[SecondViewController alloc] ...];
    self.secondNavigationController = [[UINavigationController alloc] initWithRootViewController:secondViewController];

    //Third view allocation
    ThirdViewController *thirdViewController = [[ThirdViewController alloc] ...];
    self.thirdNavigationController = [[UINavigationController alloc] initWithRootViewController:thirdViewController];


    //Now you add each of the UINavigationControllers (which is a subclass of UIViewController) to the UITabBarController.
    self.tabBarController.viewControllers = [NSArray arrayWithObjects:self.firstNavigationController,
                                             self.secondNavigationController,
                                             self.thirdNavigationController,
                                             nil];


    [self.window addSubview:self.tabBarController.view];

    [self createNavs];
}

//This is more of a 'formatNavs' now
- (void)createNavs {

    //Now you can customize each of the UINavigationController's UINavigationBars seperatly
    self.firstNavigationController.navigationBar.backgroundColor    = [UIColor colorWithHexString:@"00A3E1"];
    self.firstNavigationController.navigationBar.tintColor          = [UIColor colorWithHexString:@"00A3E1"];
    self.firstNavigationController.navigationBar.barTintColor       = [UIColor colorWithHexString:@"00A3E1"];

    self.secondNavigationController.navigationBar.backgroundColor   = [UIColor colorWithHexString:@"...."];
    self.secondNavigationController.navigationBar.tintColor         = [UIColor colorWithHexString:@"...."];
    self.secondNavigationController.navigationBar.barTintColor      = [UIColor colorWithHexString:@"...."];

    self.thirdNavigationController.navigationBar.backgroundColor    = [UIColor colorWithHexString:@"...."];
    self.thirdNavigationController.navigationBar.tintColor          = [UIColor colorWithHexString:@"...."];
    self.thirdNavigationController.navigationBar.barTintColor       = [UIColor colorWithHexString:@"...."];
}