C＃Windows应用程序计时器停止

Question

我有一个Windows应用程序，它在屏幕上使用计时器： 计时器，它用于在08:00:00（开始时间）和21:00:00（停止时间）之间每X分钟运行一个方法 在屏幕上： 下次下载起始于：显示下次运行的时间 剩余时间：显示到下次运行为止的剩余时间 下载间隔：两次运行之间的时间跨度

该方法在下次下载开始=当前时间时运行。

我的问题是该应用程序已打开并运行，计时器在一段时间后才停止。 为什么会发生这种情况，这是正常现象，还是我在代码中做错了什么（我可以在需要时将其发布，但是现在我只是想看看它是否正常）？ 有什么方法可以阻止它，或者我可以创建我自己的检查器并定期检查其状态？

提前感谢您的支持！

    private System.Windows.Forms.Timer timerFrequency = new System.Windows.Forms.Timer();

    public void LoadGeneraInfoPanel()
   {
            timerFrequency.Interval = 1000;
            timerFrequency.Enabled = true;
            this.timerFrequency.Tick += new System.EventHandler(this.timerFrequency_Tick);
            timerFrequency.Start();

        }

  private void timerFrequency_Tick(object sender, EventArgs e)
        {
            txtGICurrTime.Text = DateTime.Now.ToString("HH:mm:ss");

            if (drSystemParam["Auto"].ToString() == "True" && timerFrequency.Enabled)
            {
                if (txtGIFrequency.Text.ToString() != string.Empty && txtGIStopTime.Text.ToString() != string.Empty && txtGIStartTime.Text.ToString() != string.Empty)
                {
                    int iHours = Convert.ToInt32(txtGIFrequency.Text.Substring(0, 2));
                    int iMinutes = Convert.ToInt32(txtGIFrequency.Text.Substring(3, 2));
                    int iSeconds = Convert.ToInt32(txtGIFrequency.Text.Substring(6, 2));

                    DateTime dCurrStartTime = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day, Convert.ToInt32(txtGIStartTime.Text.Substring(0, 2)), Convert.ToInt32(txtGIStartTime.Text.Substring(3, 2)), Convert.ToInt32(txtGIStartTime.Text.Substring(6, 2)));
                    DateTime dCurrStopTime = new DateTime(DateTime.Now.Year, DateTime.Now.Month, DateTime.Now.Day, Convert.ToInt32(txtGIStopTime.Text.Substring(0, 2)), Convert.ToInt32(txtGIStopTime.Text.Substring(3, 2)), Convert.ToInt32(txtGIStopTime.Text.Substring(6, 2)));


                    DateTime dCurrStartDownloadTime = dCurrStartTime;

                    for (int j = 0; dCurrStartDownloadTime < DateTime.Now & dCurrStartDownloadTime <= dCurrStopTime; j++)
                        dCurrStartDownloadTime = dCurrStartDownloadTime.AddHours(iHours).AddMinutes(iMinutes).AddSeconds(iSeconds);

                    var result = dCurrStartDownloadTime;

                    if (DateTime.Now > dCurrStartTime && DateTime.Now < dCurrStopTime.AddHours(-iHours).AddMinutes(-iMinutes).AddSeconds(-iSeconds))
                    {
                        if (txtNextDownloadTime.Text == String.Empty)
                            txtNextDownloadTime.Text = result.ToString("HH:mm:ss");

                        TimeSpan diff = result - DateTime.Now.AddSeconds(-1);
                        txtGITimeLeft.Text = string.Format("{0}:{1}:{2}", diff.Hours.ToString().PadLeft(2, '0'), diff.Minutes.ToString().PadLeft(2, '0'), diff.Seconds.ToString().PadLeft(2, '0'));

                        if (DateTime.Now.ToString("HH:mm:ss") == txtNextDownloadTime.Text)
                        {
                            timerFrequency.Stop();
                            txtNextDownloadTime.Text = result.ToString("HH:mm:ss");
                            Thread.Sleep(800);

                            timerFrequency.Enabled = true;
                            timerFrequency.Start();

                            btnEecuteMethod_Click(sender, e);
                        }
                    }
                    else
                    {

                        result = dCurrStartTime.AddDays(1);
                        txtNextDownloadTime.Text = result.ToString("HH:mm:ss");
                        TimeSpan diff = result - DateTime.Now.AddSeconds(-1);
                        txtGITimeLeft.Text = string.Format("{0}:{1}:{2}", diff.Hours.ToString().PadLeft(2, '0'), diff.Minutes.ToString().PadLeft(2, '0'), diff.Seconds.ToString().PadLeft(2, '0'));
                    }

                }
                else
                {
                    timerFrequency.Enabled = false;
                    timerFrequency.Stop();
                }
            }
        }