private void btnLookUpUserName_Click(object sender, RoutedEventArgs e) { UserLooKUP up = new UserLooKUP(); up.SelectedClick += (obj, ev) => { if (up.SelectList != null) { if (OrgObj != null) { OrgObj.Clear(); } OrgObj = up.SelectList; string userName = ""; foreach (var item in up.SelectList) { userName += item.ObjectName + ","; } this.txtReceiveUser.Text = userName.TrimEnd(','); } }; up.Show(); }