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];
}

你可以把这个类别放在AppDelegate中。m文件。 移除UINavigation中所有默认后退按钮的文本。只有箭头“<”或设置自定义图像，如果你需要。

objective - c:

...

@end

@implementation UINavigationItem (Extension)

- (UIBarButtonItem *)backBarButtonItem {

    return [[UIBarButtonItem alloc] initWithTitle:@"" style:UIBarButtonItemStylePlain target:nil action:nil];
}

@end

所有的答案都不能解决问题。在每个视图控制器中设置后退按钮标题，并且添加偏移量仍然会使下一个视图控制器标题向右移动，这是不可接受的。

这里是使用方法swizzling的方法，只需创建新的扩展UINavigationItem

import UIKit

extension UINavigationItem {
    public override class func initialize() {

    struct Static {
        static var token: dispatch_once_t = 0
    }

    // make sure this isn't a subclass
    if self !== UINavigationItem.self {
        return
    }

    dispatch_once(&Static.token) {
        let originalSelector = Selector("backBarButtonItem")
        let swizzledSelector = #selector(UINavigationItem.noTitleBackBarButtonItem)

        let originalMethod = class_getInstanceMethod(self, originalSelector)
        let swizzledMethod = class_getInstanceMethod(self, swizzledSelector)

        let didAddMethod = class_addMethod(self, originalSelector, method_getImplementation(swizzledMethod), method_getTypeEncoding(swizzledMethod))

        if didAddMethod {
            class_replaceMethod(self, swizzledSelector, method_getImplementation(originalMethod), method_getTypeEncoding(originalMethod))
        } else {
            method_exchangeImplementations(originalMethod, swizzledMethod)
        }
    }
}

// MARK: - Method Swizzling

struct AssociatedKeys {
    static var ArrowBackButtonKey = "noTitleArrowBackButtonKey"
}

func noTitleBackBarButtonItem() -> UIBarButtonItem? {
    if let item = self.noTitleBackBarButtonItem() {
        return item
    }

    if let item = objc_getAssociatedObject(self, &AssociatedKeys.ArrowBackButtonKey) as? UIBarButtonItem {
        return item
    } else {
        let newItem = UIBarButtonItem(title: " ", style: UIBarButtonItemStyle.Plain, target: nil, action: nil)
        objc_setAssociatedObject(self, &AssociatedKeys.ArrowBackButtonKey, newItem as UIBarButtonItem?, .OBJC_ASSOCIATION_RETAIN_NONATOMIC)
        return newItem
    }
}
}

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。

我在viewDidLoad中应用了以下代码，它可以工作:

  // this will set the back button title
self.navigationController.navigationBar.topItem.title = @"Test";

 // this line set the back button and default icon color  

//[[self.navigationController.navigationBar.subviews lastObject] setTintColor:[UIColor blackColor]];

this line change the back default icon to your custom icon
[[self.navigationController.navigationBar.subviews lastObject] setTintColor:[UIColor colorWithPatternImage:[UIImage imageNamed:@"menuicon"]]];

只是更新我使用矢量图标

将标题设置为空

UIBarButtonItem *backButton = [[UIBarButtonItem alloc] initWithTitle:@""  style:UIBarButtonItemStyleDone target:self action:@selector(handleBack:)];
[backButton setTintColor:Color_WHITE];
[self.navigationItem setBackBarButtonItem:backButton];

换回图像

 UIImage *backImg = [[UIImage imageNamed:@"ic_back_white"] imageWithRenderingMode:UIImageRenderingModeAlwaysOriginal];
[UINavigationBar appearance].backIndicatorImage = backImg;
[UINavigationBar appearance].backIndicatorTransitionMaskImage = backImg;