Question

我正在创建我的第一个基于MVC示例的示例应用程序。

我有一个模特： -

 public class SampleClass
    {
        public int ID { get; set; }

        [Required]
        public string Description { get; set; }

        [Range(1,100)]
        public int Age { get; set; }

        [Display(Name="Created On")]
        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
        public DateTime CreatedDate { get; set; }

        [DataType(DataType.Date)]
        [DisplayFormat(DataFormatString = "{0:yyyy-MM-dd}", ApplyFormatInEditMode = true)]
        public DateTime? LastUpdated { get; set; }

        public string itemGenre { get; set; }

    }

一个Index.cshtml页面，显示： -

<p>
    @Html.ActionLink("Create New", "Create")
    @using (Html.BeginForm("Index", "Sample", FormMethod.Get))
    {
        <p style="margin-bottom:30px;">

            <div style="display:inline-block; float:left; border:1px dotted black; padding:20px;">
                Created Date: @Html.TextBox("fromDate")
                <input type="submit" value="Filter" />
            </div>

            <div style="display: inline-block; border: 1px dotted black; padding: 20px; margin-left:170px;">
                Genre: @Html.DropDownList("itemGenre", "All")
            </div>

            <div style="display: inline-block; float: right; border: 1px dotted black; padding: 20px;">
                Search: @Html.TextBox("searchString")
                <input type="submit" value="Filter" />
            </div>
        </p>
    }

</p>

我已经让CreatedDate和SearchString的过滤方法正常工作了。但我似乎无法让我的DropDown菜单过滤器“itemGenre”正常工作。虽然我的下拉菜单填充了我的数据库中存储的正确值/字符串，但每次进行回发时，我的控制器类中的itemGenre都会被检索为空值： -

        public ActionResult Index(DateTime? fromDate, string itemGenere, string searchString)
        {

            var GenreList = new List<string>();
            var GenreQuery = from d in db.Sample
                             orderby d.itemGenre
                             select d.itemGenre;
            GenreList.AddRange(GenreQuery.Distinct());
            ViewBag.itemGenre = new SelectList(GenreList);

            var items = from i in db.Sample
                        select i;

            if (!String.IsNullOrEmpty(searchString))
            {
                items = items.Where(o => o.Description.Contains(searchString));
            }

            if (!String.IsNullOrEmpty(Convert.ToString(fromDate)))
            {
                items = items.Where(p => p.CreatedDate >= fromDate);
            }

            if(!String.IsNullOrEmpty(itemGenere))
            {
                items = items.Where(q => q.itemGenre == itemGenere);
            }

            return View(items);

        }

我想知道我哪里出错了？

MVC dropDown Filter不回发所选值

0 个答案: