我如何自定义导航返回按钮在iOS 7及以上没有标题?(即只使用箭头)

self.navigationItem.leftBarButtonItem = self.editButtonItem;

我只是想知道它们是否有self。backbuttonitem;

OR

像这样的东西?

self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc]
                   initWithBarButtonSystemItem:UIBarButtonSystemItemBACK 
                   target:self action:@selector(back)];

当前回答

目标: 自定义UINavigationBar上的所有后退按钮为白色图标

步骤: 1. 在AppDelete的didFinishLaunchingWithOptions方法中:

UIImage *backBtnIcon = [UIImage imageNamed:@"navBackBtn"];


if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
    [UINavigationBar appearance].tintColor = [UIColor whiteColor];
    [UINavigationBar appearance].backIndicatorImage = backBtnIcon;
    [UINavigationBar appearance].backIndicatorTransitionMaskImage = backBtnIcon;
}else{

    UIImage *backButtonImage = [backBtnIcon resizableImageWithCapInsets:UIEdgeInsetsMake(0, backBtnIcon.size.width - 1, 0, 0)];
    [[UIBarButtonItem appearance] setBackButtonBackgroundImage:backButtonImage  forState:UIControlStateNormal barMetrics:UIBarMetricsDefault];

    [[UIBarButtonItem appearance] setBackButtonTitlePositionAdjustment:UIOffsetMake(0, -backButtonImage.size.height*2) forBarMetrics:UIBarMetricsDefault];
}

2.在普通超级ViewController类的viewDidLoad方法中:

 if (SYSTEM_VERSION_GREATER_THAN_OR_EQUAL_TO(@"7.0")) {
        UIBarButtonItem *backItem = [[UIBarButtonItem alloc] initWithTitle:@""
                                                                     style:UIBarButtonItemStylePlain
                                                                    target:nil
                                                                    action:nil];
        [self.navigationItem setBackBarButtonItem:backItem];
    }else{
        //do nothing
    }

其他回答

为了补充上面托马斯·C的回答,有时只放一个空格是行不通的,你必须不断地添加空格。

当你看到“导航项”下的“栏按钮项-”时,你就知道你成功了。这是在文档大纲(编辑器->显示文档大纲)。一旦你看到上面的图片,你可以删除一些空格,看看它是否仍然有效。

添加新的UIBarButtonItem到左边的UINavigationItem 改变UIBarButtonItem的使用方式 现在,点击UINavigationItem,并从outlets滑动barBackButtonItem到左UIBarButtonItem

如果你设置了导航栏的tintColor,添加一个没有标题的自定义后退按钮图像,该图像的tintColor将反映图像的颜色。请点击苹果文档链接。

https://developer.apple.com/library/content/documentation/UserExperience/Conceptual/UIKitUICatalog/index.html#//apple_ref/doc/uid/TP40012857-UIView-SW7

UINavigationItem *navItem = [[UINavigationItem alloc] init];
   navBar.tintColor = self.tintColor;

   UIImage *myImage = [UIImage imageNamed:@"left_arrow.png"];
     myImage = [myImage              imageWithRenderingMode:UIImageRenderingModeAlwaysTemplate];

     UIBarButtonItem *leftButton = [[UIBarButtonItem alloc] initWithImage:myImage style:UIBarButtonItemStylePlain target:self action:@selector(cancelButtonFunction:)];
     navItem.leftBarButtonItem = leftButton;

    navBar.items = @[ navItem ];

你可以子类化UINavigationController,将自己设置为委托,并在委托方法navigationController:willShowViewController:animated中设置backBarButtonItem:

@interface Custom_NavigationController : UINavigationController <UINavigationControllerDelegate>

@end

@implementation Custom_NavigationController

- (void)viewDidLoad
{
    [super viewDidLoad];

    self.delegate = self;
}

#pragma mark - UINavigationControllerDelegate

- (void)navigationController:(UINavigationController *)navigationController     willShowViewController:(UIViewController *)viewController animated:(BOOL)animated
{
    viewController.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}

@end

我从iOS 5开始就一直在使用这个解决方案,没有任何问题。我在视图控制器中调用了一个实用函数。你需要在viewDidLoad或之后的任何点中做。

void updateBackButtonTextForViewController(UIViewController *viewController, NSString *text)
{
    if(! viewController.navigationItem.backBarButtonItem)
    {
        viewController.navigationItem.backBarButtonItem =
        [[UIBarButtonItem alloc] initWithTitle:text
                                         style:UIBarButtonItemStylePlain
                                        target:nil action:nil];
    }
    else
    {
        viewController.navigationItem.backBarButtonItem.title = text;
    }
}

在某些情况下,导航项可能已经存在,在其他情况下需要创建它。这在不影响导航项标题的情况下解释了这两种情况。它允许你通过简单地传入@""来删除标题。