C#获取存储过程的Return返回值和Output输出参数值

//存储过程
//Create PROCEDURE MYSQL
//    @a int,
//    @b int
//AS
//    return @a + @b
//GO
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ToString());
conn.Open();
SqlCommand MyCommand = new SqlCommand("MYSQL", conn);
MyCommand.CommandType = CommandType.StoredProcedure;
MyCommand.Parameters.Add(new SqlParameter("@a", SqlDbType.Int));
MyCommand.Parameters["@a"].Value = 10;
MyCommand.Parameters.Add(new SqlParameter("@b", SqlDbType.Int));
MyCommand.Parameters["@b"].Value = 20;
MyCommand.Parameters.Add(new SqlParameter("@return", SqlDbType.Int));
MyCommand.Parameters["@return"].Direction = ParameterDirection.ReturnValue;
MyCommand.ExecuteNonQuery();
Response.Write(MyCommand.Parameters["@return"].Value.ToString());

//存储过程
//Create PROCEDURE MYSQL
//    @a int,
//    @b int,
//    @c int output
//AS
//    Set @c = @a + @b
//GO
SqlConnection conn = new SqlConnection(ConfigurationManager.ConnectionStrings["LocalSqlServer"].ToString());
conn.Open();
SqlCommand MyCommand = new SqlCommand("MYSQL", conn);
MyCommand.CommandType = CommandType.StoredProcedure;
MyCommand.Parameters.Add(new SqlParameter("@a", SqlDbType.Int));
MyCommand.Parameters["@a"].Value = 20;
MyCommand.Parameters.Add(new SqlParameter("@b", SqlDbType.Int));
MyCommand.Parameters["@b"].Value = 20;
MyCommand.Parameters.Add(new SqlParameter("@c", SqlDbType.Int));
MyCommand.Parameters["@c"].Direction = ParameterDirection.Output;
MyCommand.ExecuteNonQuery();
Response.Write(MyCommand.Parameters["@c"].Value.ToString());