自定义TraceListener的例子

这是今天课堂上的一个例子，我们实现了一个简单的SQLServerTraceListener

    class SQLServerTraceListener : TraceListener {

        public override void Write(string message)
        {
            using (SqlConnection conn =
                new SqlConnection("server=(local);database=TraceDatabase;Integrated security=true;")) {
                    using (SqlCommand cmd = conn.CreateCommand()) {
                        cmd.CommandText = "INSERT INTO Logs(Message) VALUES(@message)";
                        cmd.Parameters.Add(
                            new SqlParameter(
                                "@message", message));

                        conn.Open();
                        cmd.ExecuteNonQuery();
                        conn.Close();
                    }
            
            }
        }

        public override void WriteLine(string message)
        {
            Write(message);
        }
    }