Oracle Stored Procedure unable to call from ASP.NET - asp.net

Question

I have written a code in ASP.NET to fetch data from Oracle stored procedure. But I get an error when trying to fetch the data:
ORA-06550: line 1, column 7: PLS-00306: wrong number or types of arguments in call to 'USER_FEEDBACK' ORA-06550: line 1, column 7: PL/SQL: Statement ignored
Procedure code is this:
create or replace PROCEDURE user_feedback(cv_results out sys_refcursor,start_date IN VARCHAR2)
IS
BEGIN
open cv_results for
select pi.first_name || ' ' || pi.last_name initiator
......
from request_workflow w inner join request_workflow_attribute waRating
on waRating.request_workflow_id = w.row_id
and waRating.attr_name = 'UserRating'
.............
where w.date_stamp_utc between start_date and '31-dec-2015'
order by waRating.attr_value desc, eform_name;
END ;
This is my ASP.NET code:
Oracle.DataAccess.Client.OracleCommand objCmd = new Oracle.DataAccess.Client.OracleCommand();
objCmd.Connection = objConn;
objCmd.CommandText = "user_feedback";
objCmd.CommandType = CommandType.StoredProcedure;
Oracle.DataAccess.Client.OracleParameter oraP = new Oracle.DataAccess.Client.OracleParameter();
// System.Data.OracleClient.OracleParameter op = null;
oraP.OracleDbType = OracleDbType.RefCursor;
oraP.ParameterName = "cv_results";
oraP.Direction = System.Data.ParameterDirection.Output;
oraP.ParameterName = "start_date";
oraP.OracleDbType = OracleDbType.Varchar2;
oraP.Value = "01-Dec-2015";
oraP.Direction = System.Data.ParameterDirection.Input;
objCmd.Parameters.Add(oraP);
objConn.Open();
objCmd.ExecuteReader();
objCmd.ExecuteNonQuery();
Please suggest how to make it work.

Answer 1

You're only creating/adding a single parameter but assigning it twice with different values resulting in just one parameter to the call.
Instead, create and add two separate parameters, something like;
var oraP1 = new Oracle.DataAccess.Client.OracleParameter();
oraP1.OracleDbType = OracleDbType.RefCursor;
oraP1.ParameterName = "cv_results";
oraP1.Direction = System.Data.ParameterDirection.Output;
objCmd.Parameters.Add(oraP1);
var oraP2 = new Oracle.DataAccess.Client.OracleParameter();
oraP2.ParameterName = "start_date";
oraP2.OracleDbType = OracleDbType.Varchar2;
oraP2.Value = "01-Dec-2015";
oraP2.Direction = System.Data.ParameterDirection.Input;
objCmd.Parameters.Add(oraP2);

Answer 2

It's probably because you don't Add the first parameter. Try something like this?
...
oraP.ParameterName = "cv_results";
oraP.Direction = System.Data.ParameterDirection.Output;
objCmd.Parameters.Add(oraP);
oraP = new Oracle.DataAccess.Client.OracleParameter();
oraP.ParameterName = "start_date";
...
Though, it'd be better to declare another variable for the first param if you'll be reading from that refcursor later.