Question

我正在尝试将所选值与模型中定义的参数相关联，但现在我有错误：“值不能为空。参数名称：items“

在模型中我有：

public class ObjectivesModel
{

    [Required(ErrorMessage = "*")]
    [Display(Name = "AssociatedGoal")]
    public int AssociatedGoal { get; set; }

}

在Controler中，我创建了列表

[HttpGet]
    public ActionResult NewObjective()
    {
        IEnumerable<SelectListItem> example = new List<SelectListItem>
        {
            new SelectListItem() { Text = "ola1", Value = "1" },
            new SelectListItem() { Text = "ola2", Value = "2" }
        };

        ViewBag.GoalsToAssociate = example;

        return View();
    }

最后在视图中我有

@using (Html.BeginForm()){

             <div class="editor-label">@Html.LabelFor(o => o.AssociatedGoal)</div>
            <div class="editor-DropDownList">@Html.DropDownListFor(o => o.AssociatedGoal, new SelectList(@ViewBag.GoalsToAssociate, "Value", "Text"), "--Select Goal--")
            @Html.ValidationMessageFor(o => o.AssociatedGoal)

            </div>

因此，当我提交表单时发生错误.. 我在控制器的后期版本上有任何特殊代码

[HttpPost]
    public ActionResult NewObjective(Models.ObjectivesModel objective)
    {

        return View();
    }

Answer 1

您说在发布此表单时收到此错误。也许您没有将SelectList传递给View版[HttpPost]中的Action？

修改

响应您的修改：您还应该在SelectList版本中加入[HttpPost]代码。

MVC Razor - DropDownListFor - 帖子出错

1 个答案: