时间过期错误

Question

我的项目运作完美;但它在这个函数中一直给我这个错误：超时已过期。从池中获取连接之前经过的超时时间。这可能是因为所有池连接都在使用中并且达到了最大池大小。'

        public List<TransactionIssues> GetAllTransactions()
        {
            SqlConnection connection = new SqlConnection(connectionString);
            SqlCommand command = new SqlCommand();
            List<TransactionIssues> transIssues = new List<TransactionIssues>();
            command.CommandText = "issue_sp_getallunpostedissues";
            command.CommandType = CommandType.StoredProcedure;
            command.Connection = connection;
            SqlDataReader rdrObj;



            try
            {
                connection.Open();
                rdrObj = command.ExecuteReader();


                while (rdrObj.Read())
                {
                    TransactionIssues issues = new TransactionIssues();
                    issues.requisitionNumber = rdrObj.GetString(0);
                    issues.transactionDate = rdrObj.GetDateTime(1);
                    //issues.expense_acccount.account_desc = rdrObj.GetString(2);
                    //issues.expense_acccount.index = rdrObj.GetInt16(3);
                    issues.inventory_acccount.index = rdrObj.GetInt32(2);
                    issues.inventory_acccount.account_desc = rdrObj.GetString(3);
                    issues.docNumber = rdrObj.GetString(4);
                    issues.docType = rdrObj.GetString(5);
                    issues.items = getTransItemByRquisition(rdrObj.GetString(4));
                    transIssues.Add(issues);
                }
                rdrObj.Close();
            }
            catch (Exception ex)
            {

                throw ex;
            }
            finally
            {
                connection.Close();
            }