Stored procedure returns null as output parameter

Salaam, You can check if output is null and convert like this.

returnedSQLParameter.Value != DBNull.Value? (int)returnedSQLParameter.Value : 0;

Because it is returning DBNull.value when output sent NULL from stored procedure.

SqlCommand cmd = new SqlCommand("proc_name", conn);
cmd.CommandType = CommandType.StoredProcedure;

cmd.Parameters.Add(new SqlParameter("@p_SomeVal", SqlDbType.Int));
cmd.Parameters["@p_SomeVal"].Direction = ParameterDirection.Output;

rdr = cmd.ExecuteReader();
//...process rows...

rdr.Close();

if (cmd.Parameters["@p_SomeVal"].Value != null)
SomeVal = (int)cmd.Parameters["@p_SomeVal"].Value;

After procesing rows I added rdr.Close(); and worked fine.