一个简单的MVC实例及故障排除

Controller:

  public ActionResult Index()
         {
             string setting = "ApplicationServices";
             var connString = System.Web.Configuration.WebConfigurationManager.ConnectionStrings[setting];
             SqlConnection conn = new SqlConnection(connString.ConnectionString);
             SqlCommand cmd;
             SqlDataReader datar;
             string str_sql = "select * from T_category;";
             conn.Open();
             cmd = new SqlCommand(str_sql, conn);
             datar = cmd.ExecuteReader();
             List<string> list_categoery = new List<string>();
             while (datar.Read())
             {
                 list_categoery.Add(datar["category_name"].ToString());
             }
             conn.Close();
             ViewBag.Categories = list_categoery;

             str_sql = "select * from T_product;";
             conn.Open();
             cmd = new SqlCommand(str_sql, conn);
             datar = cmd.ExecuteReader();
             productModel pm = new productModel();
             while (datar.Read())
             {
                 pm.product_name = datar["Product_name"].ToString();
                 pm.product_description = datar["Product_description"].ToString();
                 pm.product_image = datar["Product_image"].ToString();
                 pm.product_document = datar["Product_document"].ToString();
             }
             conn.Close();
             return View(pm);
         }

View:

@model MvcApplication2.Models.productModel

@{
    Layout = null;
}

<div id="categories">
                    <ul>
                        @foreach (var cate in (ViewBag.Categories) as IEnumerable<string>)
                            {
                                <li>@cate</li>
                            }
                    </ul>
                </div>

 <section id="isBIM_models">
                <div>
                    <div id="Section_one">
                        <div id="One_product">
                            <div id="product_image">
                                <img src="~/image/isBIM_product/@(Model.product_image).jpg"/>
                            </div>
                            <div id="product_description">
                                <p>简介：<br />@Model.product_description</p>
                            </div>
                            <div class="clearfix"></div>
                            <div id="product_source">
                               <a href="~/DLL/@(Model.product_name)_DLL_2015.dll">下载</a>
                                <input type="button" id="downloadbutton"/>
                               @*<a href="~/Home/download">Click to get file</a>*@

                            </div>
                        </div>
                    </div>
                </div>
            </section>

（view中只列出了绑定模型字段的部分）

Model:

 public class productModel
    {
        public productModel() { }
        public int product_id { get; set; }
        public string product_name { get; set; }
        public string product_description { get; set; }
        public string product_image { get; set; }
        public string product_document { get; set; }

    }

如果运行时遇到这样的报错：Microsoft.CSharp.RuntimeBinder.RuntimeBinderException

则在Assemblyinfo.cs中添加一句：

[assembly: InternalsVisibleTo("MvcApplication2.Controllers")]