private static List <T> GetVisualChildCollection <T>(object parent)
where T : Visual
{
var visualCollection = new List <T>();
DataGridBehavior.GetVisualChildCollection(parent as DependencyObject, visualCollection);
return(visualCollection);
}
/// <summary>
/// Gets the visual children.
/// </summary>
/// <typeparam name="T">The type of the visuals.</typeparam>
/// <param name="parent">The parent.</param>
/// <param name="visualCollection">The collection to fill.</param>
private static void GetVisualChildCollection <T>([NotNull] DependencyObject parent, ICollection <T> visualCollection)
where T : Visual
{
var count = VisualTreeHelper.GetChildrenCount(parent);
for (var i = 0; i < count; i++)
{
var child = VisualTreeHelper.GetChild(parent, i);
if (child is T)
{
visualCollection.Add(child as T);
}
DataGridBehavior.GetVisualChildCollection(child, visualCollection);
}
}
/// <summary>
/// Called when the row number changed.
/// </summary>
/// <param name="target">
/// The target.
/// </param>
/// <param name="e">
/// The e.
/// </param>
private static void RowNumberChanged(DependencyObject target, DependencyPropertyChangedEventArgs e)
{
#pragma warning disable SA1119 // Statement must not use unnecessary parenthesis
if (!(target is DataGrid dataGrid))
#pragma warning restore SA1119 // Statement must not use unnecessary parenthesis
{
return;
}
if (!(bool)e.NewValue)
{
return;
}
void LoadedRowHandler(object sender, DataGridRowEventArgs ea)
{
if (DataGridBehavior.GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.LoadingRow -= LoadedRowHandler;
return;
}
ea.Row.Header = ea.Row.GetIndex();
}
dataGrid.LoadingRow += LoadedRowHandler;
void ItemsChangedHandler(object sender, ItemsChangedEventArgs ea)
{
if (DataGridBehavior.GetDisplayRowNumber(dataGrid) == false)
{
dataGrid.ItemContainerGenerator.ItemsChanged -= ItemsChangedHandler;
return;
}
DataGridBehavior.GetVisualChildCollection <DataGridRow>(dataGrid).ForEach(d => d.Header = new TextBlock {
Text = d.GetIndex().ToString(), HorizontalAlignment = HorizontalAlignment.Right
});
}
dataGrid.ItemContainerGenerator.ItemsChanged += ItemsChangedHandler;
}