ASP.NET MVC C#：查看记录详细信息时出现对象引用错误

我是一个 .NET 和 MVC 新手，在经历了 ASP 的长时间使用之后，我第一次学习它，现在是时候进行转换，让我构建 Web 应用程序的工作变得更加容易。

我一直在浏览 Stephen Walther 的有用视频教程来了解大多数事情，到目前为止我取得了良好的进展。我遇到困难的地方是在我的应用程序 ConversationApp 中为记录创建一个详细信息页面。列出数据和插入新数据工作正常，但每次我查看任何特定记录的详细信息页面时，我都会收到错误消息“对象引用未设置到对象的实例”。

传递给控制器​​的 URL 是： /Home/Details/X（其中 X 是记录的唯一 ID）

如果我能帮助我克服可能是我的一个非常愚蠢的错误或疏忽，我将不胜感激。

到目前为止，我的代码如下：

家庭控制器.CS

using System;
using System.Collections.Generic;
using System.Linq;
using System.Web;
using System.Web.Mvc;
using System.Web.Mvc.Ajax;
using ConversationApp.Models;

namespace ConversationApp.Controllers
{
public class HomeController : Controller
{

    private conversationDBEntities _entities = new conversationDBEntities();

    //
    // GET: /Home/

    public ActionResult Index()
    {
        return View(_entities.conversation.ToList());
    }

    //
    // GET: /Home/Details/5

    public ActionResult Details(int id)
    {

        return View();
    }

    //
    // GET: /Home/Create

    public ActionResult Create()
    {
        return View();
    } 

    //
    // POST: /Home/Create

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Create([Bind(Exclude="conversation_id")]conversation conversationToCreate)
    {
        try
        {
            // TODO: Add insert logic here
            _entities.AddToconversation(conversationToCreate);
            _entities.SaveChanges();
            return RedirectToAction("Index");
        }
        catch
        {
            return View();
        }
    }

    //
    // GET: /Home/Edit/5

    public ActionResult Edit(int id)
    {
        return View();
    }

    //
    // POST: /Home/Edit/5

    [AcceptVerbs(HttpVerbs.Post)]
    public ActionResult Edit(int id, FormCollection collection)
    {
        try
        {
            // TODO: Add update logic here

            return RedirectToAction("Index");
        }
        catch
        {
            return View();
        }
    }
}
}

详情.aspx

<%@ Page Title="" Language="C#" MasterPageFile="~/Views/Shared/Site.Master" Inherits="System.Web.Mvc.ViewPage<ConversationApp.Models.conversation>" %>

<asp:Content ID="Content1" ContentPlaceHolderID="TitleContent" runat="server">
Details
</asp:Content>

<asp:Content ID="Content2" ContentPlaceHolderID="MainContent" runat="server">

<h2>Details</h2>

<fieldset>
    <legend>Fields</legend>
    <p>
        conversation_name:
        <%= Html.Encode(Model.conversation_name) %>
    </p>
    <p>
        conversation_owner:
        <%= Html.Encode(Model.conversation_owner) %>  
    </p>
    <p>
        conversation_description:
        <%= Html.Encode(Model.conversation_description) %>
    </p>
    <p>
        conversation_homeurl:
        <%= Html.Encode(Model.conversation_homeurl) %>
    </p>
</fieldset>
<p>

    <%=Html.ActionLink("Edit", "Edit", new { id=Model.conversation_id }) %> |
    <%=Html.ActionLink("Back to List", "Index") %>
</p>

/Home/Details/X 的错误消息（其中 X 是记录的唯一 ID）

Server Error in '/' Application.
--------------------------------------------------------------------------------

Object reference not set to an instance of an object. 
Description: An unhandled exception occurred during the execution of the current web request. Please review the stack trace for more information about the error and where it originated in the code. 

Exception Details: System.NullReferenceException: Object reference not set to an instance of an object.

Source Error:

Line 13:         <p>
Line 14:             conversation_name:
Line 15:             <%= Html.Encode(Model.conversation_name) %>
Line 16:         </p>
Line 17:         <p> 

Source File: c:\Users\Michael Harris\Documents\Visual Studio 2008\Projects\ConversationApp\ConversationApp\Views\Home\Details.aspx    Line: 15 

Stack Trace: 

[NullReferenceException: Object reference not set to an instance of an object.]
ASP.views_home_details_aspx.__RenderContent2(HtmlTextWriter __w, Control parameterContainer) in c:\Users\Michael Harris\Documents\Visual Studio 2008\Projects\ConversationApp\ConversationApp\Views\Home\Details.aspx:15
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +256
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Control.Render(HtmlTextWriter writer) +10
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
ASP.views_shared_site_master.__Render__control1(HtmlTextWriter __w, Control parameterContainer) in c:\Users\Michael Harris\Documents\Visual Studio 2008\Projects\ConversationApp\ConversationApp\Views\Shared\Site.Master:26
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +256
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Control.Render(HtmlTextWriter writer) +10
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Control.RenderChildrenInternal(HtmlTextWriter writer, ICollection children) +134
System.Web.UI.Control.RenderChildren(HtmlTextWriter writer) +19
System.Web.UI.Page.Render(HtmlTextWriter writer) +29
System.Web.Mvc.ViewPage.Render(HtmlTextWriter writer) +59
System.Web.UI.Control.RenderControlInternal(HtmlTextWriter writer, ControlAdapter adapter) +27
System.Web.UI.Control.RenderControl(HtmlTextWriter writer, ControlAdapter adapter) +99
System.Web.UI.Control.RenderControl(HtmlTextWriter writer) +25
System.Web.UI.Page.ProcessRequestMain(Boolean includeStagesBeforeAsyncPoint, Boolean includeStagesAfterAsyncPoint) +1266

--------------------------------------------------------------------------------
Version Information: Microsoft .NET Framework Version:2.0.50727.4918; ASP.NET  
Version:2.0.50727.4918

在控制器上的“详细信息”操作方法中，您不会将模型传递回视图。

public ActionResult Details(int id)
{
    // get model object

    return View(//pass model object to view here);
}