顯示而不是返回查看標籤

Question

這是我查看相關代碼：

 @Html.LabelFor(model => model.nickName) 
     @Html.TextBoxFor(model => model.nickName, new { @class = "RegisterControls" }) 
     <br /><br /> 

     @Html.LabelFor(model => model.email) 
     @Html.TextBoxFor(model => model.email, new { @class = "RegisterControls" }) 
     <br /><br />    

     @Html.LabelFor(model => model.password) 
     @Html.TextBoxFor(model => model.password, new { @class = "RegisterControls" }) 

和行動方法：

public ActionResult RegisterNewUser(string uName, string email, string password) 
    { 
     ViewBag.Message = "Register"; 

     if (!users.RegisterUser(uName, email, password)) 
     { 
      ViewBag.DeniedMsg = "A user with that email already exists"; 
      return; //This doesn't work, as I should return a View 
     }    
     return PartialView("_Register");    
    } 

如果在註冊中已經存在的電子郵件地址的用戶類型（並點擊「創建帳戶」鏈接時，我想添加一個標籤，說明電子郵件已存在，並且不返回整個視圖。請參閱我的操作方法以獲得（希望）清晰度。

創建帳戶的鏈接：

@Ajax.ActionLink("Create account", "CheckifUserEmailExists", "RegisteredUsers", new AjaxOptions { UpdateTargetId = "updaterDiv" }, new { @class = "actionButtons" }) 

其實，更普遍。如果某人在文本框中輸入某些內容，則會在適當的控制器中調用操作方法。但是這個Action方法總是返回一個視圖。但是，如果您只想向該用戶顯示一條消息（例如說「創建賬戶」）並保持相同的觀點，該怎麼辦？你如何處理這個問題？我不能這樣做，因爲我必須返回一個視圖，但我想保持相同的視圖，並在那裏顯示消息

Answer 1

創建一個更多操作來返回字符串。像：

public string UserExistsMsg(string msg) 
{ 
    return msg; 
} 

，改變你的RegisterNewUser操作是這樣的：

public ActionResult RegisterNewUser(string uName, string email, string password) 
    { 
     ViewBag.Message = "Register"; 

     if (!users.RegisterUser(uName, email, password)) 
     { 
      return RedirectToAction("UserExistsMsg", "A user with that email already exists"); 
     } 
     return PartialView("_Register");    
    } 

Answer 2

更改RegisterNewUser操作是這樣的：

public ActionResult RegisterNewUser(string uName, string email, string password) 
    { 
     ViewBag.Message = "Register"; 
     String msg = ""; 
     if (!users.RegisterUser(uName, email, password)) 
     { 
      msg = "A user with that email already exists"; 
     } 
     ViewBag.DeniedMsg = msg; 
     return PartialView("_Register");    
    } 

而在局部視圖頂部打印ViewBag字符串消息。如：

@VeiwBag.DeniedMsg 

如果用戶不存在，則不會打印任何內容。