数据表仅显示表头，但不显示SQL表中的数据

Question

我正在开发一个asp.net core 2.2 Web应用程序，这是第一次使用数据表。我阅读了有关该主题的所有教程，并从Github实施了一个教程（已为我的应用程序对其进行了修改），但是一周以来，没有任何内容使它显示SQL数据库表中的任何数据。

namespace SUCOCoreControl.Controllers
{
    public class RazorBudgetController : Controller
    {
        private readonly SUCODbContext _context;

        public RazorBudgetController(SUCODbContext context)
        {
            _context = context;
        }


        // GET: /<controller>/
        public IActionResult OPEXWBS()
        {
            return View();
        }

        [HttpPost]
        public IActionResult LoadData()
        {
            try
            {
                var draw = HttpContext.Request.Form["draw"].FirstOrDefault();
                // Skiping number of Rows count
                var start = Request.Form["start"].FirstOrDefault();
                // Paging Length 10,20
                var length = Request.Form["length"].FirstOrDefault();
                // Sort Column Name
                var sortColumn = Request.Form["columns[" + Request.Form["order[0][column]"].FirstOrDefault() + "][name]"].FirstOrDefault();
                // Sort Column Direction ( asc ,desc)
                var sortColumnDirection = Request.Form["order[0][dir]"].FirstOrDefault();
                // Search Value from (Search box)
                var searchValue = Request.Form["search[value]"].FirstOrDefault();

                //Paging Size (10,20,50,100)
                int pageSize = length != null ? Convert.ToInt32(length) : 0;
                int skip = start != null ? Convert.ToInt32(start) : 0;
                int recordsTotal = 0;

                // Getting all data
                var wbsData = (from tempwbs in _context.OPEXWBS
                                    select tempwbs);
                //Sorting
                if (!(string.IsNullOrEmpty(sortColumn) && string.IsNullOrEmpty(sortColumnDirection)))
                {
                  wbsData = _context.OPEXWBS.OrderBy(sortColumn + " " + sortColumnDirection);
                }

                //Search
                if (!string.IsNullOrEmpty(searchValue))
                {
                    wbsData = wbsData.Where(m => m.OPEXWBSID.Contains(searchValue) || m.OPEXWBSENG.Contains(searchValue) || m.SubHeaderID.Contains(searchValue));
                }

                //total number of rows count
                recordsTotal = wbsData.Count();
                //Paging
                var data = wbsData.Skip(skip).Take(pageSize).ToList();
                //Returning Json Data
                return Json(new { draw = draw, recordsFiltered = recordsTotal, recordsTotal = recordsTotal, data = data });

            }
            catch (Exception)
            {
                throw;
            }

        }

               <table id="wbsTable" class="table display nowrap table-striped table-bordered" cellspacing="0" width="100%">
                    <thead>
                        <tr>
                            <th>SubHeaderID</th>
                            <th>OPEXWBSID</th>
                            <th>OPEXWBSENG</th>
                            <th>ServiceMaterialENG</th>
                            <th>ServiceMaterialARB</th>
                            <th>Edit</th>
                            <th>Delete</th>
                        </tr>
                    </thead>
                </table>
            </div>
        </div>
    </div>
</div>



@section Scripts {

    <script>

        $(function () {
            $('#wbsTable').DataTable({
                "dom": 'Bfrtip',
                "buttons": [
                'pageLength',
                'copyHtml5',
                'excelHtml5',
                'csvHtml5',
                'pdfHtml5'
            ],
            "select": true,
            "processing": true, // for show progress bar
            "serverSide": true, // for process server side
            "filter": true, // this is for disable filter (search box)
            "orderMulti": false, // for disable multiple column at once
             "ajax": {
                 "type": 'POST',
                 //"url": 'LoadData',
                 "url": "@Url.Action("LoadData", "RazorBudget")",
                 "dataSrc": "",
                 "datatype": "jason",
                 "contentType": 'application/json',
                 },
                        "columnDefs":
                            [{
                                "targets": [0],
                                "visible": false,
                                "searchable": false
                            }],
            "columns": [
            { "data": "SUBHeaderID", "name": "SUBHeaderID", "autoWidth": true },
            { "data": "OPEXWBSID", "name": "OPEXWBSID", "autoWidth": true },
            { "data": "ServiceMaterialENG", "name": "ServiceMaterialENG", "autoWidth": true },
            { "data": "ServiceMaterialARB", "name": "ServiceMaterialARB", "autoWidth": true },
            {
            "render": function (data, type, full, meta)
                { return "<a href='#' class='btn btn-info' onclick=Edit('" + full.OPEXWBSID + "'); >Edit</a>"; }
                },
                {
            data: null, render: function (data, type, row)
            {
            return "<a href='#' class='btn btn-danger' onclick=Delete('" + row.OPEXWBSID + "'); >Delete</a>" ;
                       }
                       },
                       ]
                       });
                       });
                       function DeleteData(OPEXWBSID)
                       {
                       if (confirm("Are you sure you want to delete ...?"))
                       {
                       Delete(OPEXWBSID);
                       }
                       else
                       {
                       return false;
                       }
                       }
                       function Delete(OPEXWBSID)
                       {
                       var url='@Url.Content("~/")' + "/Delete" ;
                       $.post(url, { ID: OPEXWBSID }, function (data)
                       {
                       if (data)
                       {
                       oTable=$('#wbsTable').DataTable();
                       oTable.draw();
                       }
                       else
                       {
                       alert("Something Went Wrong!");
                       }
                       });
                       }

    </script>

}

Response Headers


HTTP/2.0 200 OK
cache-control: no-cache, no-store
pragma: no-cache
content-type: text/html; charset=utf-8
server: Kestrel
x-sourcefiles: =?UTF-8?B?QzpcVXNlcnNcbW9hdGFcc291cmNlXHJlcG9zXFNVQ09Db3JlQ29udHJvbFxTVUNPQ29yZUNvbnRyb2xccmF6b3JidWRnZXRcb3BleHdicw==?=
x-powered-by: ASP.NET
date: Mon, 25 Mar 2019 09:06:57 GMT
X-Firefox-Spdy: h2

页面和表的标题（标题）正在加载，但表主体和数据未显示。

可能会出现渲染问题？还是ajax脚本中的“ URL”部分？