[英]Linking PartialView to View returns System.Web.Mvc.WebViewPage<TModel>.Model.get returned null
[英]ASP.NET MVC Nullreferenceexception: System.Web.Mvc.WebViewPage<TModel>.Model.get.<Field at offset 0x00000004> was null
我正在為學校設計一個項目(ASP.NET MVC),但是今天我遇到了這個錯誤。 我已經嘗試修復了幾個小時,但沒有任何效果。 在此應用程序中,您登錄后,您的個人資料將被加載。 這可行,但是只要我更改配置文件數據(以表單的形式),發布它並使用刷新的viewmodel返回視圖(這仍然可以正常工作),我就會得到此nullreferenceexception。 我一直在瀏覽此異常的詳細信息,但無法弄清什么是null,以及導致此異常的原因。
這是我的看法:
@model SailyWebApp.Viewmodels.HomeUserViewmodel
@{
ViewBag.Title = "Index";
Layout = "~/Views/Shared/_Layout.cshtml";
}
<body>
@if(Session["User"] != null && !string.IsNullOrEmpty(Convert.ToString(Session["User"])))
{
<h2>Profile of @Session["User"].ToString()</h2>
<form runat="server" method="post" id="userdata">
Name:<br>
<input type="text" name="Name" value="@Model.user.UserName" required /><br>
Adress:<br>
<input type="text" name="Address" value="@Model.user.Adress" required /><br>
City:<br>
<input type="text" name="City" value="@Model.user.City" required /><br>
E-mail:<br>
<input type="text" name="Mail" value="@Model.user.MailAdress" required /><br>
Phone number:<br>
<input type="text" name="Phonenumber" value="@Model.user.PhoneNumber" required /><br>
Profile description:<br>
<input type="text" name="Description" value="@Model.user.Description" required /><br>
<input type="submit" name="Save" value="Save" />
</form>
}
else{
<p>Please log in</p>
}
</body>
我的HomeController看起來像這樣:
public ActionResult Index()
{
if (Session["User"] != null)
{
User currentUser = (User)Session["User"];
HomeUserViewmodel viewmodel = new HomeUserViewmodel();
viewmodel.user = currentUser;
return View(viewmodel);
}
return View();
}
[HttpPost]
public ActionResult Index(HomeUserViewmodel viewmodel)
{
User currentUser = (User)Session["User"];
if (Logic.UserLogic.EditProfile(viewmodel.Address, viewmodel.City, viewmodel.Mail, viewmodel.Phonenumber, viewmodel.Description, currentUser.UserId))
{
currentUser = Logic.UserLogic.LoadUser(currentUser.UserId);
HomeUserViewmodel newviewmodel = new HomeUserViewmodel();
viewmodel.user = currentUser;
Session.Clear();
Session["User"] = currentUser;
return View(newviewmodel);
}
else
{
return View();
}
}
我的HomeUserViewmodel
public class HomeUserViewmodel
{
public User user;
private string name;
private string address;
private string city;
private string mail;
private string phonenumber;
private string description;
public string Name
{
get { return name; }
set { name = value; }
}
public string Address
{
get { return address; }
set { address = value; }
}
public string City
{
get { return city; }
set { city = value; }
}
public string Mail
{
get { return mail; }
set { mail = value; }
}
public string Phonenumber
{
get { return phonenumber; }
set { phonenumber = value; }
}
public string Description
{
get { return description; }
set { description = value; }
}
}
異常詳細信息:
System.NullReferenceException:'對象引用未設置為對象的實例'
System.Web.Mvc.WebViewPage.Model.get。 為空。
在此先感謝,我真的不知道在哪里可以找到此空值
if (Logic.UserLogic.EditProfile(viewmodel.Address, viewmodel.City, viewmodel.Mail, viewmodel.Phonenumber, viewmodel.Description, currentUser.UserId))
{
currentUser = Logic.UserLogic.LoadUser(currentUser.UserId);
HomeUserViewmodel newviewmodel = new HomeUserViewmodel();
viewmodel.user = currentUser; // <- It's right here, this is your problem
Session.Clear();
Session["User"] = currentUser;
return View(newviewmodel);
}
您正在錯誤的對象上填充用戶字段,要發送到視圖的視圖模型具有空字段,因此引發了空引用異常。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.