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

Hippo的回答:如果你正在使用UINavigationController,那么最好添加一个类别:

//  UINavigationController+StatusBarStyle.h:

@interface UINavigationController (StatusBarStyle)

@end



//  UINavigationController+StatusBarStyle.m:

@implementation UINavigationController (StatusBarStyle)

- (UIStatusBarStyle)preferredStatusBarStyle
{
    //also you may add any fancy condition-based code here
    return UIStatusBarStyleLightContent;
}

@end

这种解决方案可能比切换到即将被弃用的行为要好。

其他回答

Hippo的回答:如果你正在使用UINavigationController,那么最好添加一个类别:

//  UINavigationController+StatusBarStyle.h:

@interface UINavigationController (StatusBarStyle)

@end



//  UINavigationController+StatusBarStyle.m:

@implementation UINavigationController (StatusBarStyle)

- (UIStatusBarStyle)preferredStatusBarStyle
{
    //also you may add any fancy condition-based code here
    return UIStatusBarStyleLightContent;
}

@end

这种解决方案可能比切换到即将被弃用的行为要好。

对于任何仍然与此斗争的人来说,这个简单的扩展在swift中应该为您解决这个问题。

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

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.

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。

在UINavigationController上,preferredStatusBarStyle不会被调用,因为它的topViewController优先于self。所以,要在UINavigationController上调用preferredStatusBarStyle,你需要改变它的childForStatusBarStyle (Swift) / childViewControllerForStatusBarStyle (ObjC)。

建议

重写你类中的UINavigationController:

class MyRootNavigationController: UINavigationController {
    override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    override var childForStatusBarStyle: UIViewController? {
        return nil
    }
}

非推荐替代方案

要为所有UINavigationController做这件事,你可以在一个扩展中覆盖(警告:它会影响UIDocumentPickerViewController, UIImagePickerController等),但你可能不应该根据Swift文档这样做:

extension UINavigationController {
    open override var preferredStatusBarStyle: UIStatusBarStyle {
        return .lightContent
    }
    open override var childForStatusBarStyle: UIViewController? {
        return nil
    }
}