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
    }

你不能以你想要的方式访问导航backButtonItem，你需要创建自己的返回按钮，如下所示:

- (void)loadView
{
    [super loadView];
    UIButton *backButton = [[UIButton alloc] initWithFrame: CGRectMake(0, 0, 44.0f, 30.0f)];
    [backButton setImage:[UIImage imageNamed:@"back.png"]  forState:UIControlStateNormal];
    [backButton addTarget:self action:@selector(popVC) forControlEvents:UIControlEventTouchUpInside];
    self.navigationItem.leftBarButtonItem = [[UIBarButtonItem alloc] initWithCustomView:backButton];
}

当然了:

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

编辑:2014-04-09:当我获得声誉时，我感到抱歉，因为我不再使用这个技巧了。我推荐凯尔的答案。还要注意self。navigationitem。backbarbuttonitem的self不是返回按钮显示的视图控制器，而是要返回的前一个视图控制器。

如果之前的视图控制器不需要标题文本，只需用空白字符串填充标题;

self.navigationItem.title = @"";
[self.navigationController pushViewController:viewController animated:YES];

这将防止在被推送的视图控制器上显示带雪佛龙的“返回”。

编辑:即使你使用非空白标题文本，在viewWillAppear中设置前一个视图控制器的标题:除了标题可以闪烁在闪烁时，视图控制器弹出。我认为“推特应用程序”似乎做了更微妙的hack来避免闪烁。

其实很简单，我是这么做的:

Objective - C

// Set this in every view controller so that the back button displays back instead of the root view controller name
self.navigationItem.backBarButtonItem = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];

斯威夫特2

self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .Plain, target: nil, action: nil)

斯威夫特3

self.navigationItem.backBarButtonItem = UIBarButtonItem(title: "", style: .plain, target: nil, action: nil)

把这一行放到推送到堆栈(前一个视图控制器)的视图控制器中。新按下的视图控制器返回按钮现在将显示你为initWithTitle所放的任何东西，在本例中是一个空字符串。

虽然Kyle Begeman的回答完全做到了，但在每个视图控制器中都使用这种代码是相当烦人的。我最终得到了一个简单的UINavigationItem类别。小心，这里有龙!抱歉，我的意思是:

#import <objc/runtime.h>

@implementation UINavigationItem (ArrowBackButton)

static char kArrowBackButtonKey;

+ (void)load {
    static dispatch_once_t onceToken;
    dispatch_once(&onceToken, ^{
        Method m1 = class_getInstanceMethod(self, @selector(backBarButtonItem));
        Method m2 = class_getInstanceMethod(self, @selector(arrowBackButton_backBarButtonItem));
        method_exchangeImplementations(m1, m2);
    });
}

- (UIBarButtonItem *)arrowBackButton_backBarButtonItem {
    UIBarButtonItem *item = [self arrowBackButton_backBarButtonItem];
    if (item) {
        return item;
    }

    item = objc_getAssociatedObject(self, &kArrowBackButtonKey);
    if (!item) {
        item = [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStyleBordered target:nil action:NULL];
        objc_setAssociatedObject(self, &kArrowBackButtonKey, item, OBJC_ASSOCIATION_RETAIN_NONATOMIC);
    }
    return item;
}

@end

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 ];