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

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
    }
}
}

其他回答

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
    }

这在iOS6和ios7上都很有效

Xamarin (c#)选项

var buttonStyleItems = UIBarButtonItem.AppearanceWhenContainedIn(typeof(SettingsNavigationController));
buttonStyleItems.SetBackButtonTitlePositionAdjustment(new UIOffset(-1000, -1000), UIBarMetrics.Default);

objective - c选项

[[UIBarButtonItem外观]setBackButtonTitlePositionAdjustment:UIOffsetMake(-1000, -1000) forBarMetrics:UIBarMetricsDefault];

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

改变backItem。title = "" to使用topItem。标题= "" 设置navigationItem。hidesBackButton = true & navigationItem。leftBarButtonItem将失去后退手势 记住,我们必须创建2个back映像的实例

我的解决方案将改变图像和保持后面的手势:

navigationController?.navigationBar.backIndicatorImage = UIImage(named: "back")
navigationController?.navigationBar.backIndicatorTransitionMaskImage = UIImage(named: "back")
navigationController?.navigationBar.topItem?.title = ""

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。