private async void MenuItemRename_Click(object sender, RoutedEventArgs e) { var menuitem = (MenuItem)sender; var item = (GdItem)menuitem.CommandParameter; var result = await MessageBoxManager.GetMessageBoxInputWindow(new MessageBox.Avalonia.DTO.MessageBoxInputParams { ContentTitle = "Rename", ContentHeader = "inform new name", ContentMessage = "Name", WatermarkText = item.Name, ShowInCenter = true, WindowStartupLocation = WindowStartupLocation.CenterOwner, ButtonDefinitions = new ButtonDefinition[] { new ButtonDefinition { Name = "Ok" }, new ButtonDefinition { Name = "Cancel" } }, }).ShowDialog(this); if (result?.Button == "Ok" && !string.IsNullOrWhiteSpace(result.Message)) { item.Name = result.Message.Trim(); } }