TreeDataGrid Multi Selection

[hfr7]

Hi, I have question regarding the TreeDataGrid control with Multi-Selection enabled. The general setting is, that I have several parent nodes whose could have something between a hundred to several thousands child nodes. Due to performance reasons I use TreeDataGrid.

As in https://github.com/AvaloniaUI/Avalonia.Controls.TreeDataGrid/blob/master/docs/selection.md mentioned, I enable the Multi-Select by setting the bool SingleSelect = false. But it still behaved like SingleSelect = true. Then I assigned a method to ParameterSource.RowSelection.SelectionChanged event and selected the "deselected" nodes in the code behind (used the DeselectedIndexes property of the event arguments). This works out, but adds additional overhead when reselecting all previously selected nodes, especially when there are a few thousand nodes selected.

Is this a bug of TreeDataGrid or am I missing something? Any advice is welcome.

My ViewModel:

ParameterSource = new HierarchicalTreeDataGridSource<TreeViewNode>(_parameter)
{
  Columns =
  {
    new HierarchicalExpanderColumn<TreeViewNode>(
      new TextColumn<TreeViewNode, string>("Col", x => x.Name),x => x.Children)
  },
};

 ParameterSource.RowSelection!.SingleSelect = false;

My templated control, where ParameterSource is bound to:

<TreeDataGrid
	Name="TreeView"
	Source="{Binding $parent[controls:TreeView].ItemsSource}"
	>
</TreeDataGrid>

Thanks in advance 🙂