How to overwrite the FilterDistinctValues

[Suping]

Hello , I use the grid view filteringmode ="FilterRow".

and my database object return a column type is Nullable<datetime>.

When I filter this column  is null  or is not null .

Till now, everything is fine,  but, when I start scroll the gridview,  throw the blow exception. I think the exception is came from FilterDistinctValues, so, when I use the FilterRow mode, I do not need  column distinct values, Can I overwrite or set property do not call GetDistinctValue ?

 System.InvalidOperationException: The binary operator NotEqual is not defined for the types 'System.Nullable`1[System.DateTime]' and 'System.Object'.
   at System.Linq.Expressions.Expression.GetEqualityComparisonOperator(ExpressionType binaryType, String opName, Expression left, Expression right, Boolean liftToNull)
   at System.Linq.Expressions.Expression.NotEqual(Expression left, Expression right)
   at Telerik.Windows.Data.Expressions.FilterOperatorExpressionBuilderBase.GenerateIsNotNull(Expression left)
   at Telerik.Windows.Data.Expressions.FilterOperatorExpressionBuilderBase.CreateExpression(Expression left, Expression right)
   at Telerik.Windows.Data.Expressions.OperatorValueFilterDescriptorExpressionBuilderBase.CreateBodyExpression()
   at Telerik.Windows.Data.FilterDescriptor.CreateFilterExpression(ParameterExpression parameterExpression)
   at Telerik.Windows.Data.FilterDescriptorBase.CreateFilterExpression(Expression instance)
   at Telerik.Windows.Data.Expressions.FilterDescriptorCollectionExpressionBuilder.CreateBodyExpression()
   at Telerik.Windows.Data.CompositeFilterDescriptor.CreateFilterExpression(ParameterExpression parameterExpression)
   at Telerik.Windows.Data.FilterDescriptorBase.CreateFilterExpression(Expression instance)
   at Telerik.Windows.Controls.GridView.FieldFilterDescriptor.Telerik.Windows.Data.IFilterDescriptor.CreateFilterExpression(Expression instance)
   at Telerik.Windows.Data.Expressions.FilterDescriptorCollectionExpressionBuilder.CreateBodyExpression()
   at Telerik.Windows.Data.CompositeFilterDescriptor.CreateFilterExpression(ParameterExpression parameterExpression)
   at Telerik.Windows.Data.FilterDescriptorBase.CreateFilterExpression(Expression instance)
   at Telerik.Windows.Controls.GridView.ColumnFilterDescriptor.CreateFilterExpression(Expression instance)
   at Telerik.Windows.Data.Expressions.FilterDescriptorCollectionExpressionBuilder.CreateBodyExpression()
   at Telerik.Windows.Data.Expressions.FilterExpressionBuilder.CreateFilterExpression()
   at Telerik.Windows.Data.QueryableExtensions.Where(IQueryable source, CompositeFilterDescriptorCollection filterDescriptors)
   at Telerik.Windows.Data.QueryableExtensions.Where(IQueryable source, IEnumerable`1 filterDescriptors)
   at Telerik.Windows.Data.QueryableExtensions.Where(IQueryable source, FilterDescriptorCollection filterDescriptors)
   at Telerik.Windows.Controls.GridViewColumn.FilterDistinctValues(IQueryable source)
   at Telerik.Windows.Controls.GridViewColumn.GetDistinctValuesQuery(IQueryable source, Boolean filter, Nullable`1 maximumValueCount)
   at Telerik.Windows.Controls.GridViewColumn.GetDistinctValuesCore(IQueryable queryableSource, Boolean filter, Nullable`1 maximumValueCount)
   at Telerik.Windows.Controls.GridView.GridViewDataControl.GetDistinctValues(GridViewColumn column, Boolean filter, Nullable`1 maximumValueCount)
   at Telerik.Windows.Controls.GridView.GridViewDataControl.GetDistinctValues(GridViewColumn column, Boolean filter)
   at Telerik.Windows.Controls.GridView.FieldFilterControl.RefreshContent()
   at Telerik.Windows.Controls.GridView.FieldFilterControl.set_Column(GridViewColumn value)
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.RefreshFiltering()
   at Telerik.Windows.Controls.GridView.GridViewHeaderCell.OnColumnChanged(GridViewColumn oldColumn, GridViewColumn newColumn)
   at Telerik.Windows.Controls.GridView.GridViewCellBase.set_Column(GridViewColumn value)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.PrepareCell(GridViewCellBase cell, GridViewColumn column)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.GetVirtualizedCell(GridViewColumn column, Boolean createIfNull)
   at Telerik.Windows.Controls.GridView.GridViewCellsPanel.RealizeAndMeasureCells(Int32 startIndex, Int32 predictedLastIndex, Func`2 calculateNext

[Yordanka]

Hi Suping,

I have tried to reproduce the problem you report but to no avail. Could you check the attached test project? Is there something specific in your case that I have missed? 
The project uses the latest official Telerik binaries.

Regards,
Yordanka
Telerik

 

 

[Suping]

Hello  Yordanka,

Thanks your sample project,   I play with your demo project.
When I change  view model ,  public ObservableCollection<Club> Clubs  to   public VirtualQueryableCollectionView<Club> Clubs
even no data loaded (I did not check why no data)
I just drag the first column let the date column  is hidden (out of the screen)
the scroll the scrollbar , the Exception happened.

[Dimitrina]

Hello,


I am afraid we are aware of this issue. It is an issue with the virtual collection and it is already logged as a bug report.
You can follow its progress in our Feedback Portal:
VQCV: exception on filtering with nullable DataTime bound value.

Regards,
Didie
Telerik

 

 

[Suping]

Thanks, It is bug for virtual collection.
But , I still considering why in this situation still fire GetDistinctValues ?
Is it any way can avoid GetDisitnctValues  when  RefreshContent  we set FilterMode == FilterRow ?
Because in my case, the data already there, and we do not need GetDistinctValues when I scroll the grid.
And I try OnGetDistinctValue and Set e.Cancel = true.  But Still does not work.
Any idea to help me avoid this exception before you fix the virtual collection issue?
Thanks!

[Dimitrina]

Hello,

I am afraid the invocation of this method can not be stopped. It is executed no matter if the distinct values are shown on not on the FilteringControl.

Regards,
Didie
Telerik