SilverLight 4.0 C# - DomainDataSource DataGrid with CheckBox Column (UI only - not a data field) to allow user to select multiple records/rows - entity-framework

Question

New to SilverLight and to posting here. Please have mercy and be specific :)
Using RIA services with DomainDataSource and DataGrid control to display data rows from SQL server query
Goal: Have checkbox column (UI only - not a data field) to allow user to select multiple records/rows
BackGround:
1) Created new SilverLight 4, C# solution with RIA services
2) in ProjectName.Web
Created Entity Framework (EF) model referencing SQL server table/view (built solution).
Created Domain Sevice using EF model (built solution).
3) in SilverLightProjectName
From Data Sources window, dragged table onto a design surface to create DomainDataSource and DataGrid (this works great to bind DataGrid to data source)
4) in MainPage.XAML added checkbox column
What's Happening: checkboxes are selected/checked by user, scroll down, scroll back up, all checkboxes reset and ONLY Datagrid.SelectedItem is still checked. I have read this behavior is 'by design' due to paging.
<sdk:DataGrid RowStyle="{StaticResource newDataGridStyle}" AutoGenerateColumns="False" ItemsSource="{Binding ElementName=ddsPagerApp, Path=Data}" Name="vwPagerAppDataGrid" RowDetailsVisibilityMode="VisibleWhenSelected" MouseLeftButtonDown="vwPagerAppDataGrid_MouseLeftButtonDown" VerticalGridLinesBrush="#FFB9B9B9" FontSize="10" Grid.Row="3" SelectionChanged="vwPagerAppDataGrid_SelectionChanged" KeyDown="vwPagerAppDataGrid_KeyDown" MouseLeftButtonUp="vwPagerAppDataGrid_MouseLeftButtonUp" MouseRightButtonUp="vwPagerAppDataGrid_MouseRightButtonUp" DataContext="{Binding}" SelectionMode="Single" IsEnabled="True" IsReadOnly="False" TabIndex="2" Grid.Column="1" Margin="0,10,9,9">
<sdk:DataGrid.Columns>
<sdk:DataGridTemplateColumn IsReadOnly="False">
<sdk:DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<CheckBox Name="ChkSelected" IsThreeState="False" IsChecked="{Binding Path=IsChecked, Mode=TwoWay}" HorizontalAlignment="Center" VerticalAlignment="Center" Unchecked="IndividualCheckBox_Unchecked" Checked="IndividualCheckBox_Checked" Width="Auto" Height="Auto" />
</DataTemplate>
</sdk:DataGridTemplateColumn.CellEditingTemplate>
</sdk:DataGridTemplateColumn>
<sdk:DataGridTextColumn x:Name="fullNameColumn" Binding="{Binding Path=FullName}" Header="Full Name" IsReadOnly="True" />
<sdk:DataGridTextColumn x:Name="departmentColumn" Binding="{Binding Path=department}" Header="Department" IsReadOnly="True" />
<sdk:DataGridTextColumn x:Name="pager_number_displayColumn" Binding="{Binding Path=pager_number_display}" Header="Pager Number" IsReadOnly="True" />
<sdk:DataGridTextColumn x:Name="PageTo" Binding="{Binding Path=PageTo}" Header="Page To" IsReadOnly="True" />
</sdk:DataGrid.Columns>
</sdk:DataGrid>
<riaControls:DomainDataSource AutoLoad="True" d:DesignData="{d:DesignInstance my:vwPagerApp, CreateList=true}" Height="0" LoadedData="ddsPagerApp_LoadedData" Name="ddsPagerApp" QueryName="GetVwPagerAppsQuery" Width="0" Margin="10,0,25,45" Background="#FF7D0000" Foreground="#FF7D0000" Visibility="Visible">
<riaControls:DomainDataSource.DomainContext>
<my:NotifyDomainContext />
</riaControls:DomainDataSource.DomainContext>
</riaControls:DomainDataSource>
Attempt 1:
in EFModel.edmx, added Boolean Scalar Property 'IsChecked'
in DomainService.metadata.cs, added public bool IsChecked { get; set; }
in MainPage.XAML. added (above) IsChecked="{Binding Path=IsChecked, Mode=TwoWay}"
Getting error: Error 11009: Property ' ' is not mapped
UPDATE: Reversed Attempt 1:
Attempt 2:
Researching possibility of defining a partial class for the entity, wiring to DataGrid, and using that to track CheckBox values. Any advice on if this will work/how to?
Trying my best to absorb this. Please enlighten me...and thank you in advance :)

Answer 1

This is what I implemented and it worked beautifully. I hope it helps someone else in the future :)
1) SilverLight Project C#: Extend entity class using partial class (in separate file, but within same namespace – compiles into 1 class but keeps generated code separate)
namespace Pager.Web
{
public partial class pager_grp
{
bool _IsChecked = false;
public bool IsChecked
{
get
{return this._IsChecked;}
set
{this._IsChecked = !IsChecked;}
}
}
}
2) SilverLight Project GUI: Create Column in DataGrid of type DataGridTemplateColumn named chkSelected
3) SilverLight Project XAML: use template and bind to new property declared in partial class
<sdk:DataGridTemplateColumn IsReadOnly="False">
<sdk:DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<CheckBox Name="ChkSelected" IsThreeState="False" IsChecked="{Binding Path=IsChecked, Mode=TwoWay}" HorizontalAlignment="Center" VerticalAlignment="Center" Unchecked="IndividualCheckBox_Unchecked" Checked="IndividualCheckBox_Checked" Width="Auto" Height="Auto" />
</DataTemplate>
</sdk:DataGridTemplateColumn.CellEditingTemplate>
</sdk:DataGridTemplateColumn>