private void Delete_Click(object sender, EventArgs e)
{
Source.BeginUpdate();
foreach (var item in Destination.SelectedItems)
{
Source.Items.Add(item);
}
Source.EndUpdate();
Destination.BeginUpdate();
for (int i = Destination.SelectedItems.Count - 1; i >= 0; i--)
{
Destination.Items.Remove(Destination.SelectedItems[i]);
}
Destination.EndUpdate();
}