private void OnItemContainerGeneratorStatusChanged(object sender, EventArgs e)
{
if (ItemContainerGenerator.Status == GeneratorStatus.ContainersGenerated)
{
ItemContainerGenerator.StatusChanged -= OnItemContainerGeneratorStatusChanged;
CoerceValue(CanUserResizeHorizontallyProperty);
CoerceValue(CanUserResizeVerticallyProperty);
CoerceValue(DropDownHeightProperty);
}
}