WPF ComboBox with CompositeCollection - SelectedIndex not sticking

Question

I\'m using a ComboBox with a CompositeCollection as follows:

Answer 1

Since you're adding to your Collection after the ComboBox is constructed, you may have to dip into the Loaded event and set your SelectedIndex there...

<ComboBox Loaded="ComboBox_Loaded">
    <ComboBox.ItemsSource>
        <CompositeCollection>
            <ComboBoxItem Content="All" />
            <CollectionContainer Collection="{Binding Source={StaticResource AllBitsSource}}" />
        </CompositeCollection>
    </ComboBox.ItemsSource>
</ComboBox>

Code behind:

private void ComboBox_Loaded(object sender, RoutedEventArgs e)
{
    (sender as ComboBox).SelectedIndex = 0;
}