WPF DataGrid - Align Column with Autogenerated Columns

Question

I have a WPF Datagrid bounded to a DataSet; Columns are autogenerated. I need to align number columns to the right. I can use a Converter, like in this example I found on the web:

    <DataGrid x:Name="dg" ItemsSource="{Binding Source}" AutoGenerateColumns="False">
        <DataGrid.Columns>
            <DataGridTextColumn Binding="{Binding Col}" Header="Col" Width="200">
                <DataGridTextColumn.ElementStyle>
                    <Style TargetType="TextBlock">
                        <Setter Property="TextBlock.HorizontalAlignment" Value="{Binding Col, Converter={StaticResource converter}}" />
                    </Style>
                </DataGridTextColumn.ElementStyle>
            </DataGridTextColumn>
        </DataGrid.Columns>
    </DataGrid>

But in my case the column are autogenerated, so I can't use

<DataGrid.Columns>

And I don't know how to bind the property

<Setter Property="TextBlock.HorizontalAlignment" Value="{Binding Col, Converter={StaticResource converter}}" />

Any solution?

Answer 1

This may not be an ideal solution, but you could try and set the ElementStyle for each column after they have been generated by hooking a handler to AutoGeneratedColumns event.

This is what I tried:

Style

<Style TargetType="TextBlock" x:Key="ColumnStyle">
    <Setter Property="HorizontalAlignment" Value="{Binding Path=Text, RelativeSource={RelativeSource Self}, Converter={StaticResource AlignmentConverter}}" />
</Style>

XAML for DataGrid

<DataGrid x:Name="dg" 
          ItemsSource="{Binding Items}" 
          AutoGenerateColumns="True" 
          AutoGeneratedColumns="Dg_OnAutoGeneratedColumns" 
          SelectionMode="Extended"/>

EventHandler Code (Code Behind)

void Dg_OnAutoGeneratedColumns(object sender, EventArgs e)
{
    foreach (var dataGridColumn in dg.Columns)
    {
        var textColumn = dataGridColumn as DataGridTextColumn;
        if (textColumn == null) continue;

        textColumn.ElementStyle = FindResource("ColumnStyle") as Style;
    }
}

If you do not like Code Behind, then you can always create an attached behavior to achieve the same result.