iOS 15的系統(tǒng)導(dǎo)航欄背景默認(rèn)靜止時隱藏汹碱，得頁面能滑動且有內(nèi)容經(jīng)過導(dǎo)航欄區(qū)域才會顯示...

iOS15默認(rèn)樣式.GIF

解決方法

iOS 15后粘衬，需要手動設(shè)置UINavigationBar的scrollEdgeAppearance和standardAppearance屬性才行。

// OC
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    if (@available(iOS 15.0, *)) {
        UINavigationBar *navigationBar = [UINavigationBar appearance];
        
        UINavigationBarAppearance *scrollEdgeAppearance = [[UINavigationBarAppearance alloc] init];
        scrollEdgeAppearance.backgroundColor = UIColor.redColor;
        navigationBar.scrollEdgeAppearance = scrollEdgeAppearance;
        
        UINavigationBarAppearance *standardAppearance = [[UINavigationBarAppearance alloc] init];
        standardAppearance.backgroundColor = UIColor.greenColor;
        navigationBar.standardAppearance = standardAppearance;
    }
    
    return YES;
}

// Swift
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    if #available(iOS 15.0, *) {
        let navigationBar = UINavigationBar.appearance()

        navigationBar.scrollEdgeAppearance = {
            let appearance = UINavigationBarAppearance()
            appearance.backgroundColor = .red
            return appearance
        }()

        navigationBar.standardAppearance = {
            let appearance = UINavigationBarAppearance()
            appearance.backgroundColor = .green
            return appearance
        }()
    }
    
    return true
}

設(shè)置后的樣式.GIF

從效果上看的出：

• scrollEdgeAppearance：是處于頂部時的背景
• standardAppearance：是滑動后的背景

更多的自定義效果都可以在對應(yīng)的UINavigationBarAppearance實例里面設(shè)置其屬性。

如果想統(tǒng)一樣式，scrollEdgeAppearance和standardAppearance都設(shè)置同一個appearance即可（不設(shè)置任何屬性則是默認(rèn)的毛玻璃效果）：

// OC
- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    if (@available(iOS 15.0, *)) {
        UINavigationBar *navigationBar = [UINavigationBar appearance];
        
        UINavigationBarAppearance *appearance = [[UINavigationBarAppearance alloc] init];
        navigationBar.scrollEdgeAppearance = appearance;
        navigationBar.standardAppearance = appearance;
    }
    
    return YES;
}

// Swift
func application(_ application: UIApplication, didFinishLaunchingWithOptions launchOptions: [UIApplication.LaunchOptionsKey: Any]?) -> Bool {

    if #available(iOS 15.0, *) {
        let navigationBar = UINavigationBar.appearance()

        let appearance = UINavigationBarAppearance()
        navigationBar.scrollEdgeAppearance = appearance
        navigationBar.standardAppearance = appearance
    }

    return true
}

以前的樣式.GIF

That's all, thanks.