如何从子串中调用MessageBox？

Question

单击“详细信息”时如何显示messageBox？喜欢截图。

请帮我解决一下。

 try
        {
            _serviceInspector = new ServiceInspector(new Uri(serviceLocation));
        }
        catch (Exception ex)
        {
            progressBar1.Visible = false;

            lblMessage.Text = string.Format("An error (Details) occurred while attempting to find services at '{0}'.", serviceLocation);
            return;
        }