silverlight binding grid column from a comboBox using xaml element Binding - silverlight

Question

I want to add a unbound column to a a xamgrid but I want to get the value from a combox, the combobox is bound to channel object at runtime.
I tried adding the unbound column.
Tried:
<Binding Source="{StaticResource ChannelTemplate}" Path="SelectedItem.Content" />
But it doesn't seem to work
I want to bind the channelcode to the grid.
Grid,class code below.
<UI:BaseControl.Resources>
<DataTemplate x:Key="ChannelTemplate" >
<StackPanel Orientation="Horizontal" >
<TextBlock Margin="2" Text="{Binding Path=ChannelName}"/>
</StackPanel>
</DataTemplate>
</UI:BaseControl.Resources>
<ComboBox Name="CboChannel" Margin="59,6,0,0" Height="22" Width="200" VerticalAlignment="Top" HorizontalAlignment="Left" ItemTemplate="{StaticResource ChannelTemplate}" >
</ComboBox>
<ig:XamGrid Name="grdInventory" ColumnWidth="auto" ....
<ig:XamGrid.Columns>
<ig:UnboundColumn Key="Channel">
<ig:UnboundColumn.ItemTemplate>
<DataTemplate >
<TextBlock >
<TextBlock.Text >
<Binding Source="{StaticResource ChannelTemplate}" Path="SelectedItem.Content" />
</TextBlock.Text>
</TextBlock>
</DataTemplate>
</ig:UnboundColumn.ItemTemplate>
</ig:UnboundColumn>
</ig:XamGrid.Columns>
</ig:XamGrid>
Code:
Public Class Channel
Implements IDisposable
<DataMember(IsRequired:=True)>
Public Property ChannelID As Long
<DataMember()>
Public Property ChannelDescription As String
<DataMember()>
Public Property ChannelName As String
<DataMember()>
Public Property ChannelCode As String
End Class
Thanks
J

Answer 1

You could try using a DataContext pattern so that your unbound column and combobox selected item are both bound to the same value. For example (I'm using the standard data grid here):
1) Create a DataContextProxy class based on this article: http://weblogs.asp.net/dwahlin/archive/2009/08/20/creating-a-silverlight-datacontext-proxy-to-simplify-data-binding-in-nested-controls.aspx
2) Create a static resource to the DataContextProxy on the page that contains the grid and combo e.g.
<UserControl.Resources>
<Silverlight:DataContextProxy x:Key="Proxy"></Silverlight:DataContextProxy>
</UserControl.Resources>
3) Bind the SelectedValue property of your combo to an exposed property on your VM e.g.
<ComboBox Height="23"
HorizontalAlignment="Left"
SelectedValue="{Binding TestProperty, Mode=TwoWay}"
SelectedValuePath="Content"
Margin="126,54,0,0" x:Name="comboBox1"
VerticalAlignment="Top" Width="120" DisplayMemberPath="Content">
<ComboBox.Items>
<ComboBoxItem x:Name="x" Content="test2"></ComboBoxItem>
<ComboBoxItem x:Name="x2" Content="test"></ComboBoxItem>
</ComboBox.Items>
</ComboBox>
4) Bind the grid column template to the same VM property e.g.
<sdk:DataGrid AutoGenerateColumns="True"
Height="120"
HorizontalAlignment="Left"
Margin="155,153,0,0"
Name="dataGrid1"
VerticalAlignment="Top" Width="120">
<sdk:DataGrid.Columns>
<sdk:DataGridTemplateColumn Header="Test">
<sdk:DataGridTemplateColumn.CellTemplate>
<DataTemplate>
<TextBlock Text="{Binding Mode=OneWay,Source={StaticResource Proxy},Path=DataSource.TestProperty}">
</TextBlock>
</DataTemplate>
</sdk:DataGridTemplateColumn.CellTemplate>
</sdk:DataGridTemplateColumn>
</sdk:DataGrid.Columns>
</sdk:DataGrid>
This worked for me when I knocked up a quick test app. The DataGridTemplateColumn stays in sync with the selected combobox item.