ado.net獲取存儲過程的返回值

     --------------------------------------------
  假設有存儲過程如下:
  ---------------------------------------------
  
  CREATE proc sp_uptmp @tmpName varchar(50),@srcPos varchar(255)
  as
  
  Begin TRAN
   insert into t_template values(@tmpName,@srcPos)
  COMMIT
  
  return isnull(@@identity,0)
  GO
  
  
  ------------------------------------------------------------
  在 ado.Net 裡面獲取返回值的方法為(c#):
  ------------------------------------------------------------
   SqlConnection dbconn = new SqlConnection(connStr);
   SqlCommand cmd = new SqlCommand("sp_uptmp",dbconn);
   cmd.CommandType = CommandType.StoredProcedure;
  
   SqlParameter tmpName = cmd.Parameters.Add("@tmpName",SqlDbType.VarChar);
   SqlParameter srcPos = _cmd.Parameters.Add("@srcPos",SqlDbType.VarChar);
   SqlParameter rtnval = cmd.Parameters.Add("rval",SqlDbType.Int);
  
   tmpName.Direction = ParameterDirection.Input;
   srcPos.Direction = ParameterDirection.Input;
   rtnval.Direction = ParameterDirection.ReturnValue;
  
   tmpName.Value = "";
   srcPos.Value = "";
   dbconn.Open();
   cmd.ExecuteNonQuery();
   dbconn.Close();
  
   tmpid = (int)rtnval.Value; //此處即為返回值