private void AddDataSources(IList selectedItems)
{
var toRemove = new List <DataSource>();
foreach (object item in selectedItems)
{
var ds = item as DataSource;
toRemove.Add(ds);
App.Current.Dispatcher.Invoke(() => SelectedDataSources.Add(ds));
}
App.Current.Dispatcher.Invoke(() => toRemove.ForEach(ds => AvailableDataSources.Remove(ds)));
}
