我一直在研究一个使用Entity Framework（数据库优先）和Visual Studio 2012的项目。它是ASP.NET MVC项目（C＃），razor。在视图中我有一个剑道网格：
@(Html.Kendo().Grid<RunSummary>()
.Name("CheckedPatients")
.DataSource(datasource => datasource
.Ajax().PageSize(25)
.ServerOperation(false)
.Sort(sort => sort.Add("TimeOn").Descending())
.Read(read => read.Action("GetRunSummaries", "PatientReport")))
.Columns(columns =>
{
columns.Bound(c => c.UniqueId).Title(ELSORegistry.Resources.Views.Home.HomeStrings.UniqueId)
.ClientTemplate("<input type='checkbox' class='primaryBox' id='#= UniqueId #' value='#= UniqueId #'>#= UniqueId #</input>");
columns.Bound(c => c.RunNo).Title(SharedStrings.Run);
columns.Bound(c => c.Birthdate).Title(SharedStrings.Birthdate).Format("{0:g}").Filterable(true);
columns.Bound(c => c.customAge).Title(SharedStrings.Age)
.Filterable(
filterable => filterable
.UI("AgeFilter")
.Extra(false)
.Operators(operators => operators
.ForString(str => str.Clear().IsEqualTo("Is equal to"))
)
);
columns.Bound(c => c.TimeOn).Title(PatientStrings.DateOn)
.Format("{0:g}")
.Filterable(true);
columns.Bound(c => c.TimeOff).Title(PatientStrings.DateOff)
.Format("{0:g}")
.Filterable(true);
columns.Bound(c => c.DischargedAlive).Title(PatientStrings.DischargedAlive).Filterable(true);//.ClientTemplate("#= DischargedAlive ? 'Yes' : 'No' #");
columns.Bound(c => c.ShowSubmitted).Title(PatientStrings.Submitted).Filterable(true);//.ClientTemplate("#= ShowSubmitted ? 'Yes' : 'No' #");
columns.Bound(c => c.SupportTypeEnum).Title(PatientStrings.SupportType).Filterable(true);//.ClientTemplate("#= SupportType ? 'Yes' : 'No' #");
}
)
.Pageable(p => p.PageSizes(new[] {10, 25, 50, 100}))
.Sortable()
.Filterable( )
.Events( e => e.FilterMenuInit("FilterMenuFuncWithAge") ) // apply x [closing box] on pop up filter box
)
作为Kendo Grid的一个来源，我使用了一个存储过程：
CREATE PROCEDURE [dbo].[IGD_spPatientListReportFillGrid]
(@CenterId uniqueidentifier)
AS
BEGIN
SET NOCOUNT ON
-- DECLARE @start DATETIME, @end DATETIME;
-- SET @start = GETDATE();
SELECT R.RunId, R.submittedDate, R.CompletedBy, R.isRunLocked, R.LockDate, P.isPatientLocked, DATEDIFF(DAY, ISNULL
(R.submittedDate, GETDATE()), GETDATE())
AS DaysDiff, CP.CenterId, P.PatientId,
P.UniqueId,
R.RunNo,
R.SupportType,
CAST(P.Birthdate AS DATETIME) AS Birthdate,
P.Sex, P.Race,
R.Discontinuation,
R.DischargedAlive,
CAST(R.AdmitDate AS DATETIME) AS AdmitDate,YEAR(R.TimeOn) AS Year,
CAST(R.TimeOn AS DATETIME) AS TimeOn,
CAST(ISNULL(R.TimeOff,
(SELECT TOP (1) EndTime
FROM ECLS.RunDetails AS RD
WHERE (RunId = R.RunId) AND (NOT (EndTime IS NULL))
ORDER BY EndTime DESC)) AS DATETIME2) AS TimeOff,
CAST(R.DischargeDate AS DATETIME) AS DischargeDate,
CAST(R.DeathDate AS DATETIME) AS DeathDate,
DATEDIFF(day, CAST(P.Birthdate AS DATETIME), CAST(R.TimeOn AS DATETIME)) AS Age,
R.CompletedDate,
CASE WHEN (R.CompletedBy IS NULL) OR
((R.TimeOn IS NULL) OR
(R.TimeOff IS NULL)) OR
(R.CompletedBy IS NOT NULL AND ((R.TimeOn IS NULL) OR
(R.TimeOff IS NULL))) THEN 'false' ELSE 'true' END AS IsCompleted,
dbo.ELSO_IGD_CalculateAge(DATEDIFF(day, P.Birthdate,R.TimeOn)) AS customAge,
CASE WHEN (R.CompletedBy IS NULL) OR
((R.TimeOn IS NULL) OR
(R.TimeOff IS NULL)) OR
(R.CompletedBy IS NOT NULL AND ((R.TimeOn IS NULL) OR
(R.TimeOff IS NULL))) THEN 'false' ELSE 'true' END AS ShowSubmitted
FROM ECLS.Runs AS R INNER JOIN
Registry.Patients AS P ON R.PatientId = P.PatientId INNER JOIN
Registry.CenterPatients CP ON P.PatientId = CP.PatientId
WHERE CP.CenterId = @CenterId
ORDER BY R.TimeOn;
END;
我使用＆＃34;从数据库＆＃34;更新模型导入存储过程，目标类型是实体＆＃34; RunSummary＆＃34; （Kendo Grid将其用作模型）。与模型通信的过程是：
public List<RunSummary> GetRunSummariesForPatientReportGrid(Guid? centerId)
{
using (var context = new ELSORegistryEntities())
{
return context.IGD_spPatientListReportFillGrid(centerId).ToList<RunSummary>();
}
}
控制器中的代码是：
public JsonResult GetRunSummaries([ELSORegistry.Helpers.CustomDataSourceRequest] DataSourceRequest request)
{
var center = Session["Center"] as Center;
var centerId = center != null && center.CenterNo != 0 ? center.CenterId : (Guid?)null;
List<RunSummary> myList = new Repository().GetRunSummariesForPatientReportGrid(centerId);
return Json(myList.ToDataSourceResult(request), JsonRequestBehavior.AllowGet);
}
我的问题在于Kendo Grid没有显示任何内容，它是空的。在浏览器中，在Console中，我发现了错误：＆＃34; ObjectContext实例已被丢弃，不能再用于需要连接的操作＆＃34;。 （我想提一下，ShowSubmitted字段是在RunSummary的模型扩展中实现的，如下：
public bool ShowSubmitted
{
get
{
return this.LookForSubmitted();
}
}
private bool LookForSubmitted()
{
bool retVal = false;
retVal = (new Repository()).GetSubmitted(this.RunId);
return retVal;
}
public bool GetSubmitted(Guid? runId = null)
{
using (var context = new ELSORegistryEntities())
{
context.Configuration.ProxyCreationEnabled = false;
RunSummary run = context.RunSummaries.FirstOrDefault<RunSummary>(p => p.RunId == runId);
bool submitted = false;
if (run.IsCompleted == "true")
{
submitted = true;
}
else
{
submitted = false;
}
return submitted;
}
}
任何想法，如何解决问题？预先感谢您的任何帮助。
答案 0 :(得分：1)
尝试通过将以下代码段添加到DbContext类来禁用lazy loading。默认情况下，Entity Framework会延迟加载数据，这意味着在请求数据之前不会加载数据。
public AlenanDBEntities(): base("name=AlenanDBEntities")
{
this.Configuration.LazyLoadingEnabled = false;
}
如果您不想为所有实体禁用延迟加载，可以通过使用虚拟关键字声明属性来启用eagerly loading。不知道你的实体是什么样的，你会添加这样的东西
public class Run
{
public virtual List<RunSummary> RunSummaries { get; set; }
}