Timer运行一段时间后停止

 timer1.Elapsed += new System.Timers.ElapsedEventHandler(timer1_Elapsed);
 private void timer1_Elapsed(object sender, System.Timers.ElapsedEventArgs e)
        {
            timer1.Enabled = false;

            try
            {
                // 在这里对数据库进行操作 执行SQL语句或其他操作           
                m_sql.SynchronousDatabase(Str_Time);
                timer1.Interval = 3 * 1000;
            }
            catch 
            {
                
                timer1.Interval = 3 * 60 * 1000;
            }
            finally
            {
                timer1.Enabled = true;
            }
           
        }