iOS15适配 UINavigationBar和UITabBar设置无效，变成黑色以及uiscrollview为根试图无法到顶

今天更新了xcode13，运行项目发现iOS15以上的手机导航栏和状态栏之前设置的颜色等属性都不起作用了，都变成了黑色，滚动的时候才能变成正常的颜色，经确认得用UINavigationBarAppearance和UITabBarAppearance这两个属性对导航栏和状态栏设置才能生效。以下是示例代码（仅是背景颜色），具体属性根据自己实际情况进行设置

以下是代码：

    if(@available(iOS 15.0,*)){

        UINavigationBarAppearance*bar = [UINavigationBarAppearance new];

        bar.backgroundColor = [UIColor whiteColor];

        bar.backgroundEffect = nil;

        self.navigationController.navigationBar.scrollEdgeAppearance = bar;

        self.navigationController.navigationBar.standardAppearance = bar;

        UITabBarAppearance*bar2 = [UITabBarAppearance new];

        bar2.backgroundColor = [UIColor whiteColor];

        bar2.backgroundEffect = nil;

        self.tabBarController.tabBar.scrollEdgeAppearance = bar2;

        self.tabBarController.tabBar.standardAppearance = bar2;

    }

    else{

        // Fallback on earlier versions}

    }

附：uiscrollview为根视图时，无法到顶，状态栏为黑色的调整
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    if(@available(iOS 11.0, *)){

        self.contentScrollView.contentInsetAdjustmentBehavior = UIScrollViewContentInsetAdjustmentNever;

    }else {

        // Fallback on earlier versions

        self.automaticallyAdjustsScrollViewInsets = NO;

    }