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

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];

其他回答

设置返回按钮项目标题为空字符串。

[自我navigationController navigationBar。backItem setTitle: @“”);

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

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
    }
}
}

这是有效的,但它会删除前一项的标题,即使你弹出回到它:

self.navigationController.navigationBar.topItem.title = @"";

只需要在推送视图控制器的viewDidLoad上设置这个属性。

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;