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Asp.net mvc AsQueryable()返回用户未处理的NullReference异常;对象引用未设置为对象的实例;_Asp.net Mvc_Mvcjqgrid - Fatal编程技术网

Asp.net mvc AsQueryable()返回用户未处理的NullReference异常;对象引用未设置为对象的实例;

Asp.net mvc AsQueryable()返回用户未处理的NullReference异常;对象引用未设置为对象的实例;,asp.net-mvc,mvcjqgrid,Asp.net Mvc,Mvcjqgrid,我是ASP.NETMVC4.0的新手,我正在尝试使用Trirand的JQGrid从数据库填充数据。当我尝试将数据绑定到JQGrid时,我遇到了上述错误 错误在下面一行 return gridModel.MarketPriceAnalysisGrid.DataBind(oMarketPriceAnalysisModel.AsQueryable<MarketPriceAnalysisModel>()); ` 不确定可能的原因是什么? 感谢当您的MarketPriceAnalysisM

我是ASP.NETMVC4.0的新手,我正在尝试使用Trirand的JQGrid从数据库填充数据。当我尝试将数据绑定到JQGrid时,我遇到了上述错误

错误在下面一行

 return gridModel.MarketPriceAnalysisGrid.DataBind(oMarketPriceAnalysisModel.AsQueryable<MarketPriceAnalysisModel>());
`

不确定可能的原因是什么?
感谢

当您的MarketPriceAnalysisModel具有分配给jqGrid的字段而不是属性时,也会出现此错误。

MarketPriceAnalysisRepository的可能重复项。
MarketPriceAnalysisRepository.GetListofSasptComponents()
返回空值。你检查过了吗?@Dima-没有,它从数据库返回数据。我发现了问题所在。JQGrid的数据字段名称未正确映射到数据库列名。感谢@siv,我遇到了相同的问题,您的上述评论帮助我确定了我使用的一个列别名与JQGridColumn.Datafield不匹配。请将此作为答案发布,因为它可能会帮助其他人。
 // This method is called when the grid requests data
    public JsonResult SearchGridDataRequested()
    {
        // Get both the grid Model and the data Model          
        var gridModel = new MarketPriceAnalysisJQGridModel();


        // customize the default Orders grid model with our custom settings
        SetUpMarketPriceAnalysisGrid(gridModel.MarketPriceAnalysisGrid);


        var oMarketPriceAnalysisModel = MarketPriceAnalysisRepository.GetListOfSAPSPTComponents();                           

        // return the result of the DataBind method, passing the datasource as a parameter
        // jqGrid for ASP.NET MVC automatically takes care of paging, sorting, filtering/searching, etc
         return gridModel.MarketPriceAnalysisGrid.DataBind(oMarketPriceAnalysisModel.AsQueryable<MarketPriceAnalysisModel>());
    }
 IEnumerable<MarketPriceAnalysisModel> GetListOfSAPSPTComponents();
`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 MedPackMVC.Controllers.MarketPriceAnalysisController.SearchGridDataRequested() in      c:\Work\04_Dev\MedPackMVCApplication\MedPackMVC\Controllers\MarketPriceAnalysisController.cs:line 95