How to use a converter with parameter to set the header in a datagrid?

Question

I would like to set the header of a column with a converter that use a parameter. The value of the converter has to be the ItemsSource of the datagrid.

I know that to modify the text of the header I need to set the Text property of the textblock.

With this code, I can use a property in the view model of my view to set the header:

<DataGridTextColumn Binding="{Binding MyProperty}" Width="2.8cm">
    <DataGridTextColumn.Header>
        <TextBlock Text="{Binding DataContext.MyPropertyInViewModel, 
                    RelativeSource={RelativeSource AncestorType={x:Type local:MyView}}}"/>
    </DataGridTextColumn.Header>
</DataGridTextColumn>

However I prefer to use a converter for that. But I don't know how to use a converter inside the textblock of the column header. This converter need to get as value the object that is source of the datagrid.

Thanks.

Answer 1

You can get the DataGrid's ItemsSource by specifying it as RelativeSource.

Try this

<DataGridTextColumn>
    <DataGridTextColumn.Header>
        <TextBlock Text="{Binding Path=ItemsSource, 
                                  RelativeSource={RelativeSource AncestorType=DataGrid, 
                                                                 Mode=FindAncestor}, 
                                  Converter={StaticResource ValueConverter}}"/>
    </DataGridTextColumn.Header>
</DataGridTextColumn>