ContentControl two way binding within DataTemplate not working?

Question

I've setup a reusable datatemplate "DataGridCheckBoxEdit" for a datagrid column. Binding to it one way works like a charm through ContentControl. Binding directly works two way correctly. However, binding two way within that DataTemplate, from a ContentControl just won't work.

Here are the snippets:

<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<ContentControl Content="{Binding Path=IsMadeAvailable, Mode=TwoWay, UpdateSourceTrigger=PropertyChanged}" ContentTemplate="{StaticResource     DataGridCheckBoxEdit}" />
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>

and the reusable template:

<DataTemplate x:Key="DataGridCheckBoxEdit">
<CheckBox Name="CheckBoxControl" IsChecked="{Binding RelativeSource={RelativeSource Mode=FindAncestor, AncestorType=ContentControl}, Path=DataContext.Content, Mode=TwoWay, BindsDirectlyToSource=True, UpdateSourceTrigger=PropertyChanged}" Margin="8,4,2,2" />
<DataTemplate.Triggers>
<Trigger SourceName="CheckBoxControl" Property="IsVisible" Value="True">
<Setter TargetName="CheckBoxControl" Property="FocusManager.FocusedElement" Value="{Binding ElementName=CheckBoxControl}"/>
</Trigger>
</DataTemplate.Triggers>
</DataTemplate>

As I said, one way binding works like a charm...but getting the data back to the property doesn't.

Of course, putting it without being reusable:

<DataGridTemplateColumn.CellEditingTemplate>
<DataTemplate>
<CheckBox Name="GasIsAvailableCheckBox" IsChecked="{Binding Path=IsMadeAvailable, UpdateSourceTrigger=PropertyChanged}" Margin="8,4,2,2" />
<DataTemplate.Triggers>
<Trigger SourceName="GasIsAvailableCheckBox" Property="IsVisible" Value="True">
<Setter TargetName="GasIsAvailableCheckBox" Property="FocusManager.FocusedElement" Value="{Binding ElementName=GasIsAvailableCheckBox}"/>
</Trigger>
</DataTemplate.Triggers>
</DataTemplate>
</DataGridTemplateColumn.CellEditingTemplate>

also works great, and works two-way.

What am I doing wrong?

Thanks!

Vladan

H.B. H.B. · Accepted Answer · 2011-09-25T21:07:59

Your binding is just broken (see the output window of Visual Studio for the respective errors), you do not want to bind to DataContext.Content but just Content, the DataContext would be the object in that row instead of the ContentControl itself.

Change that in the binding path of the reusable template and it will work. You also set a lot of properties to values they already have by default, this would be the minimal version:

{Binding Content, RelativeSource={RelativeSource AncestorType=ContentControl}}

ContentControl two way binding within DataTemplate not working?

1 Answers