我遵循这个线程重写-preferredStatusBarStyle,但它没有被调用。 有什么选项我可以改变来启用它吗?(我在我的项目中使用xib。)


当前回答

注意,当使用self.navigationController.navigationBar.barStyle = UIBarStyleBlack;解决方案

请确保进入你的plist并设置“基于视图控制器的状态栏外观”为YES。如果不是,它将不起作用。

其他回答

所以我实际上添加了一个category到UINavigationController,但是使用了这些方法:

-(UIViewController *)childViewControllerForStatusBarStyle;
-(UIViewController *)childViewControllerForStatusBarHidden;

让它们返回当前可见的UIViewController。这让当前可见视图控制器设置它自己的首选样式/可见性。

下面是它的完整代码片段:

迅速:

extension UINavigationController {

    public override func childViewControllerForStatusBarHidden() -> UIViewController? {
        return self.topViewController
    }

    public override func childViewControllerForStatusBarStyle() -> UIViewController? {
        return self.topViewController
    }
}

在objective - c中:

@interface UINavigationController (StatusBarStyle)

@end

@implementation UINavigationController (StatusBarStyle)

-(UIViewController *)childViewControllerForStatusBarStyle {
    return self.topViewController;
}

-(UIViewController *)childViewControllerForStatusBarHidden {
    return self.topViewController;
}

@end

为了更好地衡量,这是它如何在UIViewController中实现的:

在斯威夫特

override public func preferredStatusBarStyle() -> UIStatusBarStyle {
    return .LightContent
}

override func prefersStatusBarHidden() -> Bool {
    return false
}

在objective - c中

-(UIStatusBarStyle)preferredStatusBarStyle {
    return UIStatusBarStyleLightContent; // your own style
}

- (BOOL)prefersStatusBarHidden {
    return NO; // your own visibility code
}

最后,确保你的app plist没有将“基于视图控制器的状态栏外观”设置为NO。要么删除这一行,要么将其设置为YES(我相信这是iOS 7的默认设置?)

从Xcode 11.4开始,覆盖UINavigationController扩展中的preferredStatusBarStyle属性不再有效,因为它将不会被调用。

将navigationBar的barStyle设置为.black确实有效,但如果你向navigationBar添加子视图,它可能在明暗模式下具有不同的外观,则会添加不必要的副作用。因为通过将barStyle设置为黑色,嵌入在navigationBar中的视图的userInterfaceStyle将始终具有userInterfaceStyle。不管应用程序的userinterfacstyle是暗的。

我提出的正确解决方案是通过添加UINavigationController的子类并覆盖preferredStatusBarStyle。如果你使用这个自定义的UINavigationController为你所有的视图,你将在保存侧。

对于iOS 13.4, UINavigationController类别中的preferredStatusBarStyle方法将不会被调用,swizzling似乎是唯一的选择,不需要使用子类。

例子:

分类标题:

@interface UINavigationController (StatusBarStyle)
+ (void)setUseLightStatusBarStyle;
@end

实现:

#import "UINavigationController+StatusBarStyle.h"
#import <objc/runtime.h>

@implementation UINavigationController (StatusBarStyle)

void (^swizzle)(Class, SEL, SEL) = ^(Class c, SEL orig, SEL new){
    Method origMethod = class_getInstanceMethod(c, orig);
    Method newMethod = class_getInstanceMethod(c, new);
    if(class_addMethod(c, orig, method_getImplementation(newMethod), method_getTypeEncoding(newMethod)))
        class_replaceMethod(c, new, method_getImplementation(origMethod), method_getTypeEncoding(origMethod));
    else
        method_exchangeImplementations(origMethod, newMethod);
};

+ (void)setUseLightStatusBarStyle {
    swizzle(self.class, @selector(preferredStatusBarStyle), @selector(_light_preferredStatusBarStyle));
}

- (UIStatusBarStyle)_light_preferredStatusBarStyle {
    return UIStatusBarStyleLightContent;
}    
@end

在AppDelegate.h中的用法:

#import "UINavigationController+StatusBarStyle.h"

[UINavigationController setUseLightStatusBarStyle];

Swift 4.2及以上版本

正如所选答案中提到的,根本原因是检查您的窗口根视图控制器对象。

流结构的可能情况

Custom UIViewController object is window root view controller Your window root view controller is a UIViewController object and it further adds or removes navigation controller or tabController based on your application flow. This kind of flow is usually used if your app has pre login flow on navigation stack without tabs and post login flow with tabs and possibly every tab further holds navigation controller. TabBarController object is window root view controller This is the flow where window root view controller is tabBarController possibly every tab further holds navigation controller. NavigationController object is window root view controller This is the flow where window root view controller is navigationController. I am not sure if there is any possibility to add tab bar controller or new navigation controller in an existing navigation controller. But if there is such case, we need to pass the status bar style control to the next container. So, I added the same check in UINavigationController extension to find childForStatusBarStyle

使用以下扩展,它处理所有上述场景-

extension UITabBarController {
    open override var childForStatusBarStyle: UIViewController? {
        return selectedViewController?.childForStatusBarStyle ?? selectedViewController
    }
}

extension UINavigationController {
    open override var childForStatusBarStyle: UIViewController? {
        return topViewController?.childForStatusBarStyle ?? topViewController
    }
}

extension AppRootViewController {
    open override var preferredStatusBarStyle: UIStatusBarStyle {
        return children.first { $0.childForStatusBarStyle != nil }?.childForStatusBarStyle?.preferredStatusBarStyle ?? .default
    }
}

在info中你不需要UIViewControllerBasedStatusBarAppearance键。Plist默认为true

对于更复杂的流程,需要考虑的要点

In case you present new flow modally, it detaches from the existing status bar style flow. So, suppose you are presenting a NewFlowUIViewController and then add new navigation or tabBar controller to NewFlowUIViewController, then add extension of NewFlowUIViewController as well to manage further view controller's status bar style. In case you set modalPresentationStyle other than fullScreen while presenting modally, you must set modalPresentationCapturesStatusBarAppearance to true so that presented view controller must receive status bar appearance control.

注意,当使用self.navigationController.navigationBar.barStyle = UIBarStyleBlack;解决方案

请确保进入你的plist并设置“基于视图控制器的状态栏外观”为YES。如果不是,它将不起作用。