void ButtonDelete_Click(object sender, RoutedEventArgs e) { Device device = new Device(); device = ((Button)sender).DataContext as Device; SystemMessages sm = new SystemMessages(new Message() { UserMessage = "Do you want to delete device?", SystemMessage = "Device Acronym: " + device.Acronym, UserMessageType = MessageType.Confirmation }, ButtonType.YesNo); sm.Closed += new EventHandler(delegate(object popupWindow, EventArgs eargs) { if ((bool)sm.DialogResult) { m_client.DeleteDeviceAsync(device.ID); } }); sm.ShowPopup(); }