WPF Gridview MUCH slower than WinForms when using child table

[Ivan]

Hello,

Our application uses gridviews to display hierarchical data using two separate data tables that share a key for lookup purposes.

The application previously used WinControls RadGridView and joined the two tables using a GridViewRelation. 

                this.Grid.BeginUpdate();
                this.Grid.MasterTemplate.Reset();
                Grid.DataSource = datatables[0];
                if (AddDetails)
                {
                    GridViewTemplate template = new GridViewTemplate();
                    template.DataSource = datatables[1];
                    Grid.Templates.Add(template);
 
                    GridViewRelation relation = new GridViewRelation(Grid.MasterTemplate);
                    relation.ChildTemplate = template;
                    relation.RelationName = "Details";
                    relation.ParentColumnNames.Add(PC);
                    relation.ChildColumnNames.Add(CC);
                    Grid.Relations.Add(relation);
                 }

 





Once loaded, the lookup was very fast, i.e. I could expand any row to view the child data more or less 
instantly.

 
However when I switched over to the WPF gridview, performance for the same input became 
unacceptably slow, for example it takes 
approximately 2 seconds every time to expand a row to view the child data.

The WPF xaml looks like so:
   <Grid>
        <telerik:RadGridView x:Name="BugGrid"
                             IsFilteringAllowed="True"
                             IsReadOnly="True"
                             CanUserInsertRows="False"
                             TabIndex="1"
                             AutoGenerateColumns="False"
                             DataLoading="DataLoading"
                             RowHeight="32"
                             MaxColumnWidth="200"
                             EnableRowVirtualization="True"
                             EnableColumnVirtualization="True"
                             DataLoadMode="Asynchronous"
                            
                             >
                             
            <telerik:RadGridView.Columns>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding asdfas}"/>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding Blah}"/>
                <telerik:GridViewDataColumn DataMemberBinding="{Binding PC}" IsVisible="False"/>
            </telerik:RadGridView.Columns>
            
            <telerik:RadGridView.ChildTableDefinitions>
                <telerik:GridViewTableDefinition x:Name="Details">
                    <telerik:GridViewTableDefinition.Relation>
                        <telerik:TableRelation>
                            <telerik:TableRelation.FieldNames>
                                <telerik:FieldDescriptorNamePair 
                                    ParentFieldDescriptorName="PC" 
                                    ChildFieldDescriptorName="CC"/>
                            </telerik:TableRelation.FieldNames>
                        </telerik:TableRelation>
                    </telerik:GridViewTableDefinition.Relation>
                </telerik:GridViewTableDefinition>
            </telerik:RadGridView.ChildTableDefinitions>
        </telerik:RadGridView>
    </Grid>


In the code behind I define the properties of the child table in DataLoading

        private void DataLoading(object sender, GridViewDataLoadingEventArgs e)
        {       
            GridViewDataControl dataControl = (GridViewDataControl) sender;
            if (dataControl.ParentRow != null)
            {
                dataControl.AutoGenerateColumns = false;
                dataControl.ShowGroupPanel = false;
                dataControl.IsFilteringAllowed = false;
                dataControl.CanUserFreezeColumns = false;
                dataControl.IsReadOnly = true;
                GridViewDataColumn column = new GridViewDataColumn();
                column.DataMemberBinding = new Binding("CC");
                column.IsVisible = false;
                column = new GridViewDataColumn();
                column.DataMemberBinding = new Binding("Name");
                dataControl.Columns.Add(column);
                column = new GridViewDataColumn();
                column.DataMemberBinding = new Binding("Value");
                dataControl.Columns.Add(column);
            }




I set the data source of the child table definition to the be the data table with the details.



I've been able to determine that it's the looking up of the appropriate child data from 

the data table that is the very slow part (e.g. if the details data table is blank, 

the rows expand instantly) but why is it SO much slower than 
the old WinControls grid, which also worked with the same data using a similar Relationship.



More importantly, how can I speed it up?

[Yordanka]

Hi Ivan,

Thank you for reporting this problem.
We managed to reproduce it locally but we cannot say what is causing it. We will make a profound investigation and we will notify you as soon as we have progress.
Please, excuse us for the inconvenience caused.
 
Kind regards,
Yordanka
the Telerik team