Razor 语法初级使用，不断更新此文章

 1  public ActionResult Index()
 2         {
 3             if (Session["username"] == null)
 4             {
 5                 Response.Redirect("/Login/Index");
 6             }
 7             else
 8             {
 9                 ViewData["username"] = Session["username"].ToString();
10             }       
11             return View();
12         }

1  <a href="#" class="dropdown-toggle" data-toggle="dropdown" role="button"
2                            aria-expanded="false">
3                             <i class="fa fa-user-o fa-fw"></i>
4                             @if (ViewData["username"]!=null)
5                             {
6                                     @ViewData["username"].ToString();
7                             }                            
8                             <span class="caret"></span>
9                         </a>