按下后退按钮时，前一个屏幕上的导航标题消失

Question

我的导航栏标题有问题。我有 2 个屏幕，当我单击屏幕 2 上的返回按钮时，它将返回屏幕 1，但屏幕 1 的标题消失了。这是我的 sn-p 代码

screen1 .m

    - (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    self.title = @"title 1";
....

屏幕 2 .m

- (void)viewDidLoad
{
    [super viewDidLoad];
    // Do any additional setup after loading the view.

    self.title = self.stringTitle;

    // change the back button and add an event handler
    self.navigationItem.hidesBackButton = YES;
    //set custom image to button if needed
    UIImage *backButtonImage = [UIImage imageNamed:@"btn_back.png"];
    UIButton *button = [UIButton buttonWithType:UIButtonTypeCustom];
    [button setImage:backButtonImage forState:UIControlStateNormal];
    button.frame = CGRectMake(-12, 2, backButtonImage.size.width, backButtonImage.size.height);
    [button addTarget:self action:@selector(backAction) forControlEvents:UIControlEventTouchUpInside];

    UIView *backButtonView = [[UIView alloc] initWithFrame:CGRectMake(0, 0, backButtonImage.size.width-15, backButtonImage.size.height)];
    [backButtonView addSubview:button];

    UIBarButtonItem *customBarItem = [[UIBarButtonItem alloc] initWithCustomView:backButtonView];
    self.navigationItem.leftBarButtonItem = customBarItem;

    self.navigationController.navigationBar.titleTextAttributes = @{NSForegroundColorAttributeName: [UIColor whiteColor]};
....
}

- (void) backAction
{
    [self.navigationController popViewControllerAnimated:YES];
}

我尝试了几种技巧来使屏幕 1 的标题出现以下技巧：

1. 在viewwillappear 方法上设置标题

   - (void)viewWillAppear:(BOOL)animated{self.title = @"tes";}
   

2. 在viewdidappear 方法上设置标题

    - (void)viewDidAppear:(BOOL)animated{
    self.navigationController.navigationBar.topItem.title = @"YourTitle";
     self.title = @"tes";
     }
   

但标题仍然消失。请帮忙

---

这是我移动到下一个屏幕的方式

- (IBAction)btGenerateTokenAction:(id)sender {
    SofttokenResultController *controller = [[SofttokenResultController alloc] initWithNibName:@"SofttokenResultController" bundle:nil];

    controller.navigationController.navigationBar.backItem.title = @"Kembali";
    [ViewLoadingUtil animateToNextView:controller from:self :@""];
}

+ (void) animateToNextView:(UIViewController *)controller from:(UIViewController *)fromController :(NSString *)navTitle{

    NSLog(@"animateToNextView called");

    [fromController.navigationController pushViewController:controller animated:YES];
}

Answer 1

这解决了我的问题：

override func viewWillAppear(animated: Bool) {
        super.viewWillAppear(animated: animated)
        self.navigationItem.title="Title text"
}

Answer 2

就我而言，问题出在backItem?.title。在我的视图控制器和UINavigationController 的自定义子类中，我将其设置为空字符串：

func navigationController(_ navigationController: UINavigationController, willShow viewController: UIViewController, animated: Bool) {
    ...
    navigationController.navigationBar.backItem?.title = ""
}

我的猜测是，当使用popViewController(animated:) 时，标题取自backItem?.title 并设置到主标题属性中。

Answer 3

在viewWillAppear 中实现这个：

self.navigationItem.title="Title text";

Answer 4

它通常发生在你设置 backItem?.title = "" 时，因为后台控制器的标题是从这个属性中获取的 我几个月来一直面临这个问题，只是通过评论这一行来解决它

Answer 5

为我工作的解决方案。你可以试试这个：

override func viewWillAppear(animated: Bool) {
    super.viewWillAppear(animated)

    self.navigationController?.navigationBar.topItem?.title = ""
    self.navigationItem.title = "Title"
}

Answer 6

Objective c解决方案：

- (void) viewWillAppear:(BOOL)animated {
    [super viewWillAppear: animated];
    self.navigationItem.title = @"Title text";
}

Answer 7

我来自 Swift 世界。但是我尝试了很多解决方案。这些都是动画造成的。如果您将 Bool 更改为 false，它将解决您的问题。最后，您可以将代码放入 viewWillAppear 函数中。

override func viewWillAppear(animated: Bool) {
    if animated {
        //...
    }
}