Question

  C# code 
 public class customer
   {
    [Required]
    [Display(Name = "Country")]
    public int CountryId { get; set; } 
   }

ViewBag.CountryId = new SelectList（Uow.Countries.GetAll（），“Id”，“Name”）;

  modelbuilder 
       modelBuilder.Entity<Customer>().HasRequired(p => p.Country)
                                      .WithMany(p => p.Customers)
                                      .HasForeignKey(p => p.CountryId)
                                      .WillCascadeOnDelete(false);




      <div class="control-group">
        @Html.LabelFor(model => model.CountryId, "CountryId", new { @class = "control-    label" })
          <div class="controls">
         @Html.DropDownList("CountryId","select country"); 
         @Html.ValidationMessageFor(model => model.CountryId, null, new { @class =  "help-inline" })
        </div>
        </div>

点击默认值为“保存”按钮时，我没有收到模型错误 “选择国家”“ 相反，我收到错误“ 具有键'CountryId'的ViewData项的类型为'System.Int32'，但必须是'IEnumerable'类型

Answer 1

您下拉列表中的

CountryId为Model.CountryId，而不是ViewBag.CountryId。试试这个：

@Html.DropDownListFor(model => model.CountryId, (SelectList)ViewBag.CountryId,"select country");

我还建议您为集合选择不同的名称，并为获取选定值的属性选择。

模型不会为MVC中的默认值下拉列表生成错误

1 个答案: