public bool ShowDlg(object sender, out object selected) { _sender = (ComboBox)sender; if (_sender != null) { if (_sender.GetType() == typeof(ComboBox)) { //(_sender).IsEnabled = false; (_sender).IsDropDownOpen = false; } Helper(_sender); selected = Return(objType, enumerable.ToArray()); return (bool)this.DialogResult; } ComboPopUp_Closing(this, null); try { selected = _sender.Items.GetItemAt(0); return false; } catch { selected = null; return false; } }