Handle output parameter of an Oracle stored procedure using C# code

Question

I'm using Oracle database. I have a table called Room and then I made this stored procedure:

 CREATE OR REPLACE PROCEDURE RETRIEVEROOM
 (RoomID IN INTEGER, RID_Out OUT INTEGER) 
 AS
 BEGIN
    Select Room.RoomNumber INTO RID_Out 
    From Room 
    Where Room.RoomNumber = RoomID;
 END;

So I'm trying to send input and output parameters using C# with this code:

private void loadRooms()
{
            OracleCommand cmd = new OracleCommand();
            cmd.Connection = conn;
            cmd.CommandText = "RETRIEVEROOM";
            cmd.CommandType = CommandType.StoredProcedure;

            cmd.Parameters.Add("RoomID", 218);  // Here I send the input parameter
            cmd.Parameters.Add("RID_Out", "").Direction = ParameterDirection.Output; 
            cmd.Parameters["RID_Out"].Size = 255; 
            cmd.ExecuteNonQuery();
            MessageBox.Show(cmd.Parameters["RID_Out"].ToString(), "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);
}

When I try to print the value of output parameter in the MessageBox, It prints "RID_Out" not the value of RID_Out which should be 218 . How can I solve this problem?

Answer 1

Guess you want to print Value property of the parameter.

MessageBox.Show((string)cmd.Parameters["RID_Out"].Value, "Error", MessageBoxButtons.OK, MessageBoxIcon.Error);