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.

Tyson的答案是正确的改变状态栏颜色为白色在UINavigationController。

如果有人想通过在AppDelegate中编写代码来实现相同的结果，那么请使用下面的代码并在AppDelegate的didFinishLaunchingWithOptions方法中编写它。

不要忘记在。plist文件中设置UIViewControllerBasedStatusBarAppearance为YES，否则更改将不会反映。

Code

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {
     // status bar appearance code
     [[UINavigationBar appearance] setBarStyle:UIBarStyleBlack];

     return YES;
}

如果有人正在使用一个导航控制器，并希望他们所有的导航控制器都有黑色风格，你可以在Swift 3中写一个扩展到UINavigationController，它将应用于所有的导航控制器(而不是一次分配给一个控制器)。

extension UINavigationController {

    override open func viewDidLoad() {
        super.viewDidLoad()

        self.navigationBar.barStyle = UIBarStyle.black
    }

}

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.

这是我解决这个问题的方法。

定义一个名为AGViewControllerAppearance的协议。

AGViewControllerAppearance.h

#import <Foundation/Foundation.h>

@protocol AGViewControllerAppearance <NSObject>

@optional

- (BOOL)showsStatusBar;
- (BOOL)animatesStatusBarVisibility;
- (UIStatusBarStyle)preferredStatusBarStyle;
- (UIStatusBarAnimation)prefferedStatusBarAnimation;

@end

在UIViewController上定义一个名为Upgrade的类别。

UIViewController+Upgrade.h

#import <UIKit/UIKit.h>

@interface UIViewController (Upgrade)

//
//  Replacements
//

- (void)upgradedViewWillAppear:(BOOL)animated;

@end

UIViewController+Upgrade.m

#import "UIViewController+Upgrade.h"

#import <objc/runtime.h>

#import "AGViewControllerAppearance.h" // This is the appearance protocol

@implementation UIViewController (Upgrade)

+ (void)load
{
#pragma clang diagnostic push
#pragma clang diagnostic ignored "-Wselector"
    Method viewWillAppear = class_getInstanceMethod(self, @selector(viewWillAppear:));
#pragma clang diagnostic pop
    Method upgradedViewWillAppear = class_getInstanceMethod(self, @selector(upgradedViewWillAppear:));
    method_exchangeImplementations(viewWillAppear, upgradedViewWillAppear);
}

#pragma mark - Implementation

- (void)upgradedViewWillAppear:(BOOL)animated
{
    //
    //  Call the original message (it may be a little confusing that we're
    //  calling the 'same' method, but we're actually calling the original one :) )
    //

    [self upgradedViewWillAppear:animated];

    //
    //  Implementation
    //

    if ([self conformsToProtocol:@protocol(AGViewControllerAppearance)])
    {
        UIViewController <AGViewControllerAppearance> *viewControllerConformingToAppearance =
        (UIViewController <AGViewControllerAppearance> *)self;

        //
        //  Status bar
        //

        if ([viewControllerConformingToAppearance respondsToSelector:@selector(preferredStatusBarStyle)])
        {
            BOOL shouldAnimate = YES;

            if ([viewControllerConformingToAppearance respondsToSelector:@selector(animatesStatusBarVisibility)])
            {
                shouldAnimate = [viewControllerConformingToAppearance animatesStatusBarVisibility];
            }

            [[UIApplication sharedApplication] setStatusBarStyle:[viewControllerConformingToAppearance preferredStatusBarStyle]
                                                        animated:shouldAnimate];
        }

        if ([viewControllerConformingToAppearance respondsToSelector:@selector(showsStatusBar)])
        {
            UIStatusBarAnimation animation = UIStatusBarAnimationSlide;

            if ([viewControllerConformingToAppearance respondsToSelector:@selector(prefferedStatusBarAnimation)])
            {
                animation = [viewControllerConformingToAppearance prefferedStatusBarAnimation];
            }

            [[UIApplication sharedApplication] setStatusBarHidden:(! [viewControllerConformingToAppearance showsStatusBar])
                                                    withAnimation:animation];
        }
    }
}

@end

现在，是时候说你的视图控制器正在实现AGViewControllerAppearance协议。

例子:

@interface XYSampleViewController () <AGViewControllerAppearance>

... the rest of the interface

@end

当然，你可以实现其余的方法(showsStatusBar, animatesStatusBarVisibility, prefereredstatusbaranimation)从协议和UIViewController+升级将做适当的 基于它们提供的值进行定制。

除了serenn的回答，如果你用modalPresentationStyle(例如.overCurrentContext)呈现一个视图控制器，你也应该在新呈现的视图控制器上调用这个:

presentedViewController.modalPresentationCapturesStatusBarAppearance = true

不要忘记在呈现的视图控制器中重写preferredStatusBarStyle。