System.Data.EntityCommandExecutionException 问题

Question

dbo.Images - 表格

http://imgur.com/9YVNfZz

图像.cs

 public class Image
        {
            public int ID { get; set; }
            public string ImagePath { get; set; }
            public string Category { get; set; }
        }
        public class ImageDBContext : DbContext
        {
            public DbSet<Image> Images { get; set; }
        }
    }

ImageController.cs

       [HttpGet]
public ActionResult Search(string category) 
{
    var myList = db.Images.ToList();
    if (!string.IsNullOrEmpty(category))
    {
        myList = db.Images.Where(s => s.Category == category).ToList();
    }

    return View(myList);
}

Search.cshtml

    @model IEnumerable<MvcMovie.Models.Image>

@{
    ViewBag.Title = "Search";
}
  <button>@Html.ActionLink("Extras", "Search", new { category = "Extras" })</button>
<button>@Html.ActionLink("Home", "Search", new { category = "Home" })</button>

<div style="width:800px; margin:200px auto;  text-align:center;">
    <ul class="images">
        @foreach (var item in Model)
        {
            var imagePath = @item.ImagePath;
            imagePath = "/Images/" + imagePath;
            <li class="image-item" style="background: url(@imagePath) no-repeat;"></li>
        }
    </ul>

应用程序上面的代码当前将在dbo.Images 中找到的所有图像显示到具有两个按钮的search.cshtml 上，以便从包含Extras 或Home 的Category 中过滤987654331@表。尽管该页面应根据单击的 Category 按钮显示图像，但我遇到了如下错误。

• 点击按钮 - https://i.imgur.com/tEEvLLt.jpg

任何想法如何解决它？ 感谢您的帮助，并在此先感谢您。

Answer 1

您可以将所选类别作为查询字符串参数发送到您的控制器，然后在那里过滤您的列表。请注意，ActionLinks 将针对您的 HttpGetaction 方法。将值替换为您拥有的类别。此外，这种方法不需要data 属性。

      <button>@Html.ActionLink("Category1", "Search", new { category = "Category1" })</button>
      <button>@Html.ActionLink("Category2", "Search", new { category = "Category2" })</button>
      <button>@Html.ActionLink("Category3", "Search", new { category = "Category3" })</button>


     <ul class="images">
       @foreach (var item in Model)
       {
          var imagePath = @item.ImagePath;
          imagePath = "/Images/" + imagePath;
          <li class="image-item" style="background: url(@imagePath) no-repeat;"></li>
      }
     </ul>

控制器：

  [HttpGet]
  public ActionResult Search(string category) // <-- selected category
  {
    var myList = db.Images.ToList();
    if(!string.IsNullOrEmpty(category)){
          myList = db.Images.Where(s => s.Category == category).ToList();
    }

    return View(myList);
  }

Answer 2

试试这样的。在这种方法中，用户可以从下拉列表中选择一个类别并单击搜索按钮。

控制器

    private ImageDBContext db = new ImageDBContext ();

    [HttpGet]
    public ActionResult Index()
    {
        var myList = db.Images.ToList();

        return View(myList);
    }

    [HttpPost]
    public ActionResult Index(string category)
    {
        var myList = db.Images.ToList();

        if (string.IsNullOrEmpty(category) || category == "All")
            return PartialView("_SearchResult", myList);

        if (!string.IsNullOrEmpty(category))
            myList = myList.Where(m => m.Category == category).ToList();

        return PartialView("_SearchResult", myList);
    }

部分视图：_SearchResult

@model IEnumerable<MvcMovie.Models.Image>

<ul class="images">
    @foreach (var item in Model)
    {
        var imagePath = @item.ImagePath;
        imagePath = "/Images/" + imagePath;
        <li class="image-item" data-filter="Fashion" data-filter-    type="@item.Category.ToLower()" style="background: url(@imagePath) no-repeat; height: 200px;">@item.Category</li>
    }
</ul>

查看

@model IEnumerable<MvcMovie.Models.Image>

<script src="@Url.Content("~/Scripts/jquery-1.10.2.js")" type="text/javascript"></script>
<script src="@Url.Content("~/Scripts/jquery.unobtrusive-ajax.js")" type="text/javascript"></script>

@using (Ajax.BeginForm("Index", "Search", new AjaxOptions { HttpMethod = "POST", InsertionMode = InsertionMode.Replace, UpdateTargetId = "result" }))
{
    <select name="category">
        <option>All</option>
        <option>Home</option>
        <option>Extras</option>
    </select>
    <input type="submit" value="Search" />
}

<div style="width: 800px; margin: 200px auto; text-align: center;">
    <div id="result">
        @Html.Partial("_SearchResult", Model)
    </div>
</div>