Why 'wrong number of parameters' error in this call to a stored procedure?

Question

A stored procedure exists that inserts a new record and returns the newly generated record ID. This stored procedure is called from a WinForms application but at the ExecuteNonQuery time an exception is thrown indicating that the wrong number of parameters
has been supplied. If I take out the one parameter that is marked as ParameterDirection.Output then the ExecuteNonQuery does not throw an exception.
CREATE PROCEDURE [dbo].[API_InsertIntoManu]
@Name nvarchar(50),
@Description nvarchar(2000)
AS
SET NOCOUNT ON
INSERT INTO Manu (
[Name],
[Description]
VALUES (
@Name,
@Description
SELECT SCOPE_IDENTITY() As InsertedID
END
GO
The C# code that calls the above SP looks like this:
using (SqlConnection conn = new SqlConnection( "<snipped>" ))
using (SqlCommand cmd = new SqlCommand( "[dbo].[API_InsertIntoManu]", conn ))
cmd.CommandType = CommandType.StoredProcedure;
cmd.Parameters.Add( Name, SqlDbType.NVarChar, 50 ).Value = "some name";
cmd.Parameters.Add( Title, SqlDbType.NVarChar, 200 ).Value = "some title";
// This parameter is supposed to receive the new row's ID but instead triggers a 'wrong number of args' exception.
cmd.Parameters.Add( "InsertedID",SqlDbType.Int ).Direction = ParameterDirection.Output;
conn.Open();
// This is where the exception gets thrown.
cmd.ExecuteNonQuery();
iReturn = (int)cmd.Parameters[InsertedID].Value;
Richard Lewis Haggard

Answer 1

In you sp the size of Title var is 2000 and not 200, correct this:
cmd.Parameters.Add( "@Title", SqlDbType.NVarChar, 200 ).Value
Fouad Roumieh