iOS self.navigationController.navigationBar.barTintColor 无效问题

在开发中使用self.navigationController.navigationBar.barTintColor 设置颜色无效时，可使用以下方案解决

      if(@available(iOS 15.0,*)){
        UINavigationBarAppearance *apperance=[[UINavigationBarAppearance alloc]init];
        apperance.backgroundColor = [UIColor colorWithRed:(34/255.0) green:(34/255.0)  blue:(34/255.0) alpha:1.0];//设置背景色
        [apperance setTitleTextAttributes:@{
          NSFontAttributeName:[UIFont systemFontOfSize:17],
          NSForegroundColorAttributeName:[UIColor whiteColor]
        }];//设置标题字体
        apperance.shadowImage = [[UIImage alloc]init];
            apperance.shadowColor = [UIColor clearColor];//分割线去除
        [UINavigationBar appearance].standardAppearance = apperance;
        [UINavigationBar appearance].scrollEdgeAppearance = [UINavigationBar appearance].standardAppearance;//重新赋值
      } else {
        self.navigationBar.barTintColor = [UIColor colorWithRed:(34/255.0) green:(34/255.0)  blue:(34/255.0) alpha:1.0];
      }