适配iOS15导航栏，导航栏空白, 修改导航栏文字颜色

适配iOS15导航栏，导航栏空白, 修改导航栏文字颜色:

    if (@available(iOS 15.0, *)) {
        UINavigationBarAppearance *barApp = [UINavigationBarAppearance new];
        barApp.backgroundColor = [UIColor colorWithHexString:themeColorStr];
//        barApp.shadowColor = [UIColor whiteColor];
        
        NSDictionary *dic = @{NSForegroundColorAttributeName : [UIColor whiteColor],
                                  NSFontAttributeName : [UIFont systemFontOfSize:AdaptedWidth(18) weight:UIFontWeightMedium]};
        
        barApp.titleTextAttributes = dic;
        
        UINavigationBar.appearance.standardAppearance = barApp;
        UINavigationBar.appearance.scrollEdgeAppearance = barApp;
    }