WPF - How to stop an ItemsControl psuedo-grid's columns from dancing/jumping around during layout

Question

Several other questions on SO have come to the same conclusion I have -- using an ItemsControl with a DataTemplate for each item constructed to position items such that they resemble a grid is much simpler (especially to format) than using a ListView.

The code resembles:

<StackPanel Grid.IsSharedSizeScope="True">
  <!-- Header -->
  <Grid>
    <Grid.ColumnDefinitions>
      <ColumnDefinition Width="Auto" SharedSizeGroup="Column1" />
      <ColumnDefinition Width="Auto" SharedSizeGroup="Column2" />
    </Grid.ColumnDefinitions>
    <TextBlock Grid.Column="0" Text="Column Header 1" />
    <TextBlock Grid.Column="1" Text="Column Header 2" />
  </Grid>
  <!-- Items -->
  <ItemsControl ItemsSource="{Binding Path=Values, Mode=OneWay}">
    <ItemsControl.ItemTemplate>
      <DataTemplate>
        <Grid>
          <Grid.ColumnDefinitions>
            <ColumnDefinition Width="Auto" SharedSizeGroup="Column1" />
            <ColumnDefinition Width="Auto" SharedSizeGroup="Column2" />
          </Grid.ColumnDefinitions>
          <TextBlock Grid.Column="0" Text="{Binding ColumnProperty1}" />
          <TextBlock Grid.Column="1" Text="{Binding ColumnProperty2}" />
        </Grid>
      </DataTemplate>
    </ItemsControl.ItemTemplate>
  </ItemsControl>
</StackPanel>

The problem I'm seeing is that whenever I swap the object to which the ItemsSource is bound (it's an ObservableCollection that I replace the reference to, rather than clear and re-add), the entire 'grid' dances about for a few seconds.

Presumably it is making a few layout passes to get all the Auto-width columns to match up.

This is very distracting for my users and I'd like to get it sorted out. Has anyone else seen this?

Answer 1

Unfortunately I wasn't been able to reproduce the problem with the code provided. I've tried it swapping samples of 20 up to 1000 items, and with 100 different widths inside the collection. Nothing was dancing. On huge collections (200 and higher) UI used to hang for a while and then release, showing new grid with the items provided.