asp.net - jqGrid ASP.NET MVC2 数据绑定(bind) NullReferenceException

Question

我正在尝试 JQGrid ASP.NET MVC2 版本。

创建模型和 Controller :

    var itemsGridModel = new OrderItemsjqGridModel();
    itemsGridModel.OrderItemsGrid.DataUrl = Url.Action("ItemsDataRequested", new {OrderID = OrderID, CustomerID = CustomerID });
    orderVM.orderItemsGrid = itemsGridModel;


    return View(orderVM);

请求的项目数据:

public JsonResult ItemsDataRequested(int OrderID, int CustomerID)
{
    // Get both the grid Model and the data Model

    var gridModel = new OrderItemsjqGridModel();
    var orderItems = ordersRepository.GetOrder(OrderID).ItemsInOrders.ToList();

    IQueryable<ItemsInOrder> myItems = orderItems.AsQueryable<ItemsInOrder>();

    return gridModel.OrderItemsGrid.DataBind(myItems);
}

我在最后一行得到一个 NullReferenceException。myItems 有 1 个项目，所有值都已填充。

知道我做错了什么吗？

谢谢。

堆栈跟踪:

   at Trirand.Web.Mvc.Util.PrepareJsonResponse(JsonResponse response, JQGrid grid, DataTable dt)
   at Trirand.Web.Mvc.Util.ConvertToJson(JsonResponse response, JQGrid grid, DataTable dt)
   at Trirand.Web.Mvc.JQGrid.FilterDataSource(Object dataSource, NameValueCollection queryString, IQueryable& iqueryable)
   at Trirand.Web.Mvc.JQGrid.GetJsonResponse()
   at Trirand.Web.Mvc.JQGrid.DataBind()
   at Trirand.Web.Mvc.JQGrid.DataBind(Object dataSource)
   at TechRun.UI.Controllers.OrdersController.ItemsDataRequested(Int32 OrderID, Int32 CustomerID) in y:\work\yosi\source\Techrun\TechRun.UI\Controllers\OrdersController.cs:line 118
   at lambda_method(Closure , ControllerBase , Object[] )
   at System.Web.Mvc.ActionMethodDispatcher.Execute(ControllerBase controller, Object[] parameters)
   at System.Web.Mvc.ReflectedActionDescriptor.Execute(ControllerContext controllerContext, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethod(ControllerContext controllerContext, ActionDescriptor actionDescriptor, IDictionary`2 parameters)
   at System.Web.Mvc.ControllerActionInvoker.<>c__DisplayClassd.<InvokeActionMethodWithFilters>b__a()
   at System.Web.Mvc.ControllerActionInvoker.InvokeActionMethodFilter(IActionFilter filter, ActionExecutingContext preContext, Func`1 continuation)

型号:

public class OrderItemsjqGridModel
{
    public JQGrid OrderItemsGrid { get; set; }

public OrderItemsjqGridModel()
{            
    OrderItemsGrid = new JQGrid
                     {
                         Columns = new List<JQGridColumn>()
                         {
                             new JQGridColumn { DataField = "OrderID", 
                                                // always set PrimaryKey for Add,Edit,Delete operations
                                                // if not set, the first column will be assumed as primary key
                                                PrimaryKey = true,
                                                Editable = false,
                                                Width = 30 },
                             new JQGridColumn { DataField = "ItemID",
                                                PrimaryKey = true,
                                                Editable = true,
                                                Width = 120},
                             new JQGridColumn { DataField = "ItemDescription", 
                                                Editable = true,
                                                Width = 300},
                             new JQGridColumn { DataField = "NumOfItems", 
                                                Editable = true,
                                                Width = 50
                                                },
                             new JQGridColumn { DataField = "CostOfItem", 
                                                Editable = true,
                                                Width = 75 },
                             new JQGridColumn { DataField = "TotalCost",
                                                Editable =  false
                                              },
                             new JQGridColumn { DataField = "SuppolyDate", 
                                                Editable = true,
                                                Width = 120, 
                                                DataFormatString = "{0:d}" },
                         },
                         Width = Unit.Pixel(640),
                         Height = Unit.Percentage(100)
                     };

    OrderItemsGrid.ToolBarSettings.ShowRefreshButton = true;
    OrderItemsGrid.ToolBarSettings.ShowAddButton = true;
    OrderItemsGrid.ToolBarSettings.ShowDeleteButton = true;
    OrderItemsGrid.ToolBarSettings.ShowEditButton = true;
}

}

Answer 1

我知道这是一个老问题，但我一直在寻找相同问题的解决方案，但没有成功，我返回到我的代码进行更多异常分析，我找到了解决方案，我更愿意在这里记录它所以遇到同样问题的任何人都会感到满意。

我发现了原因，模型 JGridColumn 名称与返回的 SQL 查询字段不同，其中一个模型列中存在拼写错误。

确保所有 JGrid 列的名称与 SQL 查询列的名称相同。