ios - UINavigationBar 后退按钮在某些设备或模拟器上显示 "Back"标题，在其他设备或模拟器上显示之前的 View Controller 标题

Question

我有一个带有导航栏的应用程序，可以从一个 View Controller 导航到下一个 View Controller 。在某些模拟器和设备上导航到下一个 View Controller 时，后退按钮标题是“返回”，而在某些模拟器和设备上，后退按钮标题是第一个 View Controller 的标题。

我很想知道为什么？

这不是更改后退按钮上的文本的问题。问题是在某些模拟器和设备上我看到了“后退”标题，而在某些模拟器和设备上我看到了前一个 Controller 的标题。在 20 多个模拟器和设备上进行了测试。

代码如下:

应用委托(delegate)

#import "AppDelegate.h"
#import "FirstViewController.h"
#import "SecondViewController.h"

@interface AppDelegate ()
@property (nonatomic, strong) UINavigationController *navigationController;
@end

@implementation AppDelegate

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions
{
   FirstViewController *firstViewController = [[FirstViewController alloc]
                                              initWithNibName:nil
                                              bundle:nil];

    self.navigationController = [[UINavigationController alloc]
                                 initWithRootViewController:firstViewController];

    self.window = [[UIWindow alloc]
                   initWithFrame:[[UIScreen mainScreen]bounds]];

    self.window.rootViewController = self.navigationController;

    self.window.backgroundColor = [UIColor whiteColor];

    [self.window makeKeyAndVisible];


    return YES;
}

第一个 View Controller

#import "FirstViewController.h"
#import "SecondViewController.h"

@interface FirstViewController ()
@property (nonatomic, strong) UIButton *btnDisplaySecondViewController;
@end

@implementation FirstViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}


-(void)performDisplaySecondViewController:(id)paramSender{
    SecondViewController *secondControllrt = [[SecondViewController alloc]
                                              initWithNibName:nil bundle:nil];
    [self.navigationController pushViewController:secondControllrt
                                         animated:YES];
}


- (void)viewDidLoad
{
    [super viewDidLoad];
    self.title = @"First Controller";

    self.btnDisplaySecondViewController = [UIButton
                                           buttonWithType:UIButtonTypeSystem];

    [self.btnDisplaySecondViewController
     setTitle:@"Display Seconf View Controller"
     forState:UIControlStateNormal];

    [self.btnDisplaySecondViewController sizeToFit];

    self.btnDisplaySecondViewController.center = self.view.center;

    [self.btnDisplaySecondViewController addTarget:self
                                            action:@selector(performDisplaySecondViewController:) forControlEvents:UIControlEventTouchUpInside];

    [self.view addSubview:self.btnDisplaySecondViewController];


    UIImageView *imageView =
    [[UIImageView alloc]
     initWithFrame:CGRectMake(0.0, 0.0, 100.0f, 40.0f)];

    imageView.contentMode = UIViewContentModeScaleAspectFit;

    UIImage *image = [UIImage imageNamed:@"ios7_0135"];

    [imageView setImage:image];

    self.navigationItem.titleView = imageView;
}

第二个 View Controller

#import "SecondViewController.h"

@interface SecondViewController ()

@end

@implementation SecondViewController

- (id)initWithNibName:(NSString *)nibNameOrNil bundle:(NSBundle *)nibBundleOrNil
{
    self = [super initWithNibName:nibNameOrNil bundle:nibBundleOrNil];
    if (self) {
        // Custom initialization
    }
    return self;
}


- (void)viewDidLoad
{
    [super viewDidLoad];
    self.title = @"Second Controller";
}

Answer 1

当您设置当前 View Controller 的标题时，当您移动到下一个 View Controller 时，它将自动设置在导航栏中的 Back 位置。如果您没有设置当前 View Controller 的标题，那么 iOS 会自动显示 Back 标题。

要设置 View Controller 的标题，请使用以下代码:

self.title = @"<title>";

我想你会从解释中明白这一点。