SqlConnection sqlConn = new SqlConnection("...");
            
            SqlCommand testCMD = new SqlCommand("myProc", sqlConn);
            testCMD.CommandType = CommandType.StoredProcedure;
            SqlParameter par1 = testCMD.Parameters.Add("@p1", SqlDbType.VarChar, 10);
            par1.Direction = ParameterDirection.Input;
            par1.Value = "aaaa";

            SqlParameter par2 = testCMD.Parameters.Add("@p2", SqlDbType.Int);
            par2.Direction = ParameterDirection.Input;
            par2.Value = 0;


            SqlParameter par3 = testCMD.Parameters.Add("@p3", SqlDbType.Int);
            par3.Direction = ParameterDirection.Input;
            par3.Value = 0;

            SqlParameter Res = testCMD.Parameters.Add("@p4", SqlDbType.Int);
            Res.Direction = ParameterDirection.ReturnValue;

            sqlConn.Open();
            SqlDataReader myReader = testCMD.ExecuteReader();