無法將類型'CustomPrincipal'轉換爲'System.Security.Principal.IPrincipal'

Question

我已按照此guide向IPrincipal添加自定義特性。

protected void Application_PostAuthenticateRequest(Object sender, EventArgs e) 
    { 
     HttpCookie authCookie = Request.Cookies[FormsAuthentication.FormsCookieName]; 
     if (authCookie != null) 
     { 
      FormsAuthenticationTicket authTicket = FormsAuthentication.Decrypt(authCookie.Value); 
      JavaScriptSerializer serializer = new JavaScriptSerializer(); 
      CustomPrincipalSerializeModel serializeModel = serializer.Deserialize<CustomPrincipalSerializeModel>(authTicket.UserData); 
      CustomPrincipal newUser = new CustomPrincipal(authTicket.Name); 
      newUser.UserId = serializeModel.UserId; 
      newUser.FirstName = serializeModel.FirstName; 
      newUser.LastName = serializeModel.LastName; 
      HttpContext.Current.User = newUser; /This line makes an error. 
     } 
    } 

這是最後一行發生錯誤。

Cannot implicitly convert type 'SocialMedia.Models.CustomPrincipal' to 'System.Security.Principal.IPrincipal'. An explicit conversion exists (are you missing a cast?)

可能是爲什麼它不起作用的問題。

Answer 1

的錯誤是很清楚，你是分配給User財產的情況下，需要IPrincipal型的情況下，我懷疑你的CustomPrincipal類不是從IPrinicipal接口繼承，那是因爲你所看到的錯誤。

Answer 2

更改最後一行：

HttpContext.Current.User = (IPrincipal)newUser; 

編輯

確保ICustomPrincipal擴展IPrincipal接口。