sqlinfomessage 事件为什么没有响应

请各位高手帮忙看看我的代码,为什么我的infomessage事件不会触发的?谢谢
namespace TestApplication
{
    public partial class Form1 : Form
    {
        static string InfoMessageTest;
        public Form1()
        {
            InitializeComponent();
        }
        protected static void OnInfoMessage(object sender, SqlInfoMessageEventArgs args)
        {            foreach (SqlError err in args.Errors)
            {                InfoMessageTest = string.Format("The {0} has received a severity {1}, state {2} error number {3}\n" +
                "on line {4} of procedure {5} on server {6}:\n{7}",
                err.Source, err.Class, err.State, err.Number, err.LineNumber,
                err.Procedure, err.Server, err.Message);
            }
        }        private void Form1_Load(object sender, EventArgs e)
        {
            string sqlconstr = string.Format("Data Source=D2E68F9FFD37481;Initial Catalog=Northwind;Integrated Security=True");
            SqlConnection sqlcon = new SqlConnection(sqlconstr);
            sqlcon.InfoMessage += new SqlInfoMessageEventHandler(OnInfoMessage);
            SqlCommand sqlcom = new SqlCommand("select * from orders", sqlcon);
            sqlcom.Connection.Open();
            sqlcom.ExecuteNonQuery();
            sqlcom.Connection.Close();
            textBox1.Text = InfoMessageTest;
        }    }
}