Windows Community Toolkit数据网格的ComboBox绑定问题

<controls:DataGrid ItemsSource="{x:Bind ViewModel.Items}">
    <controls:DataGrid.Columns>
        <controls:DataGridTextColumn Header="Name" Binding="{Binding Name}" />
        <controls:DataGridComboBoxColumn Header="Category" SelectedValueBinding="{Binding CategoryId}" DisplayMemberPath="CategoryName" SelectedValuePath="CategoryId" >
            <controls:DataGridComboBoxColumn.ElementStyle>
                <Style TargetType="ComboBox">
                    <Setter Property="ItemsSource" Value="{x:Bind ViewModel.Categories}" />
                </Style>
            </controls:DataGridComboBoxColumn.ElementStyle>
            <controls:DataGridComboBoxColumn.EditingElementStyle>
                <Style TargetType="ComboBox">
                    <Setter Property="ItemsSource" Value="{x:Bind ViewModel.Categories}" />
                </Style>
            </controls:DataGridComboBoxColumn.EditingElementStyle>
        </controls:DataGridComboBoxColumn>
    </controls:DataGrid.Columns>
</controls:DataGrid>