如何将Entity Framework 6绑定到KendoUI Grid

Question

我用两个表创建了一个测试SQL Server数据库：WorkItem和WorkItemNote。它们之间有一个外键，因此一个WorkItem可以具有许多WorkItemNote记录。我试图在Kendo网格中显示WorkItems。该Action返回Json，但网格中未显示任何内容。
如果我仅使用要显示的属性创建一个匿名对象，它将起作用。这表示具有关系（WorkItemNote）的实体（WorkItem）无法显示在Kendo网格中。
有没有办法解决？

我的网格：

<div>
    @(Html.Kendo().Grid<TryToLoadGrid.Models.WorkItem>()
        .Name("grid")
        .HtmlAttributes(new { style = "height:380px;" } )
        .Sortable()
        .Pageable()
        .DataSource(dataSource => dataSource.Ajax().Read(read => read.Action("GetActiveWorkItems", "Home")))
        .Columns(columns =>
            {
                columns.Bound(workItem => workItem.Title);
                columns.Bound(workItem => workItem.Description);
            }
        )
    )
</div>

我的动作代码是：

 public ActionResult GetActiveWorkItems([DataSourceRequest]DataSourceRequest request)
 {
     using (TaskManagerContext context = new TaskManagerContext())
     {
         IQueryable<WorkItem> list = context.WorkItems.Where(x => x.IsActive == true);
         DataSourceResult result = list.ToDataSourceResult(request);
         return Json(result);
     }
 }

从“动作”中可以看出，我对网格的WorkItemNotes甚至都不感兴趣。

为了证明这是由于这种关系造成的，我创建了第二个Action，它可以正常工作并显示数据：

  public ActionResult GetActiveWorkItems2([DataSourceRequest]DataSourceRequest request)
  {
      using (TaskManagerContext context = new TaskManagerContext())
      {
          List<WorkItem> list = context.WorkItems.Where(x => x.IsActive == true).ToList();
          List<Object> dataObjects = new List<object>();
          foreach (WorkItem workItem in list)
          {
              dataObjects.Add(new { Title = workItem.Title, Description = workItem.Description });
          }

          DataSourceResult result = dataObjects.ToDataSourceResult(request);
          return Json(result);
      }
  }

有没有办法解决？

Answer 1

我个人认为直接在用户界面中使用实体框架模型是一种不好的做法。您应该从模型中提取所需的数据，并将其放置在视图模型中。然后，您将视图模型列表返回给客户端。

public class WorkItemViewModel 
{
    public Int64 ID { get; set; }
    public string Title { get; set }
    public string Desctription { get; set }
}


public ActionResult GetActiveWorkItems2([DataSourceRequest]DataSourceRequest request)
{
    using (TaskManagerContext context = new TaskManagerContext())
    {
        List<WorkItem> list = context.WorkItems.Where(x => x.IsActive == true).ToList();
        List<WorkItemViewModel> dataObjects = new List<WorkItemViewModel>();
        foreach (WorkItem workItem in list)
        {
            dataObjects.Add(new WorkItemViewModel { Title = workItem.Title, Description = workItem.Description });
        }
        return Json(dataObjects.ToDataSourceResult(request));
    }
}


<div>
    @(Html.Kendo().Grid<ViewModelNamespace.WorkItemViewModel>()
        .Name("grid")
        .HtmlAttributes(new { style = "height:380px;" } )
        .Sortable()
        .Pageable()
        .DataSource(dataSource => dataSource.Ajax().Read(read => read.Action("GetActiveWorkItems", "Home")))
        .Columns(columns =>
            {
                columns.Bound(workItem => workItem.ID).Hidden();
                columns.Bound(workItem => workItem.Title);
                columns.Bound(workItem => workItem.Description);
            }
        )
    )
</div>