DataGrid: How to display a numbered row index as the first column?

[kg-github]

I thought this would be an easy one but there doesn't seem to be a built-in way to display a row index as the first column of a DataGrid. I have a simple collection of items that I would like to display row numbers for (starting at 1). Anyone have a suggestion?

[Diyari-Kurdi]

You can use the LoadingRow event to set row headers in code-behind and the Primitives package to customize the RowHeader background.

 <controls:DataGrid
     xmlns:wctprimitives="using:CommunityToolkit.WinUI.UI.Controls.Primitives"
     x:Name="MyDataGrid"
     HeadersVisibility="All"
     LoadingRow="MyDataGrid_LoadingRow"
     RowHeaderWidth="50">
     <controls:DataGrid.RowHeaderStyle>
         <Style TargetType="wctprimitives:DataGridRowHeader">
             <Setter Property="Background" Value="Transparent" />
         </Style>
     </controls:DataGrid.RowHeaderStyle>
     <controls:DataGrid.Resources>
         <SolidColorBrush x:Key="DataGridColumnHeaderBackgroundColor" Color="Transparent" />
     </controls:DataGrid.Resources>
     <controls:DataGrid.Columns>
         <!--  Columns  -->
     </controls:DataGrid.Columns>
 </controls:DataGrid>

    private void ProductsDataGrid_LoadingRow(object sender, CommunityToolkit.WinUI.UI.Controls.DataGridRowEventArgs e)
    {
        e.Row.Header = (e.Row.GetIndex() + 1).ToString();
    }