Question

How can I find the DataGridTextColumn from the HeaderTemplate template? Is there a way to perform this using only XAML? I have tried FindAncestor of type DataGridTextColumn but it is not found.

I know DataGridTextColumn is not part of the visual tree. Is there any workaround for this?

Answer 1

Do you really need the whole column object? The DataContext will be whatever you pass in as header, e.g.

<DataGridTextColumn Header="Name" Binding="{Binding Name}">
    <DataGridTextColumn.HeaderTemplate>
        <DataTemplate>
            <TextBlock Text="{Binding}" Foreground="Red" />
        </DataTemplate>
    </DataGridTextColumn.HeaderTemplate>
</DataGridTextColumn>

This will cause a red header with the text “Name”.

If you actually need the column you could use an ElementName binding:

<DataGrid ItemsSource="{Binding Data}">
    <DataGrid.Columns>
        <DataGridTextColumn x:Name="nameColumn" Header="Name" Binding="{Binding Name}">
            <DataGridTextColumn.HeaderTemplate>
                <DataTemplate>
                    <TextBlock Foreground="Red">
                        <Run Text="{Binding Mode=OneWay}" />
                        <Run Text=" - " />
                        <Run Text="{Binding ActualWidth, ElementName=nameColumn, Mode=OneWay}" />
                    </TextBlock>
                </DataTemplate>
            </DataGridTextColumn.HeaderTemplate>
        </DataGridTextColumn>
    </DataGrid.Columns>
</DataGrid>

This shows “Name” and the column width in the header.