在特定时间执行特殊功能的Windows服务

Question

I have a Windows Service that Monitors a Network folder for a file and on Creation moves that File and does some transfiguration. This works great.

My question is, if a file has not been saved to the Monitored Location by 9:30am I need to have my service send out a reminder email. I was hoping not to have to write a 2nd program for this which is what seems to be a common suggestion(2nd program with Scheduled Task).

So, what are my options? I assume that I can make this work using a Timer in some fashion but I understand that is not the best idea. Is there a way to have a Scheduled Task make my Service execute a specific function?

Thanks for any ideas...

EDIT: for reference I am currently researching Quartz.NET , just seemed like overkill at first...

Answer 1

我没有看到使用计时器有什么不对，使用System.Timers.Timer并设置间隔为例如5分钟，然后在Elapsed事件检查当前时间，如果9:30传递发送邮件。

Answer 2

Personnaly, I'd suggest System.Threading.Timer in the same service.

Something like this:

using System;
using System.Threading;

public class Foo
{
    private Timer _timer;
    private readonly static TimeSpan TIME_OF_DAY = new TimeSpan(9, 30, 0);

    public void Main()
    {
        var now = DateTime.Now;
        var nextDt = now.Date.AddDays(1).Add(TIME_OF_DAY); 
        _timer = new Timer(TimerCallback, null, (int)nextDt.Subtract(now).TotalMilliseconds, Timeout.Infinite);
    }

    public void TimerCallback(object state)
    {
        try
        {
            // Reminder
        }
        finally
        {
            try
            {
                var now = DateTime.Now;
                var nextDt = now.Date.AddDays(1).Add(TIME_OF_DAY);
                _timer.Change((int)nextDt.Subtract(now).TotalMilliseconds, Timeout.Infinite);
            }
            catch (ObjectDisposedException) { }
        }
    }
}

Answer 3

I would also recommend a second program to do the checking and to send the email since it's not easy to communicate with a service. It may seem like duplication but it will be easier to develop and maintain in the long run.

Rather than having the service send the email, have the second program send the email. If you want to reuse code from the service, add the service project as a reference to the second program.

That may be easier said than done but it should be easier than trying to have the second program communicate with the service in some way since you'd have to wire the communication mechanism yourself.

Answer 4

You have two questions in your post. 1. You need a scheduler to check at 9.30 AM everyday 2. If it is not saved you need to notify via email.

Actually Quartz.NET is very simple to use. I am currently using Quartz.NET for one of my schedule tasks to run. You just need to write 4-5 lines of code and have the job scheduling part done.

Coming to your email you can use log4net. Log4net has something called SMTPAppender. All your configurations related to log4net you can specify in your web or app.config itself. Its also very simple and pretty straight forward. A sample log4net configuration for SMTPAppender will look like below:

<configuration>
  <configSections>
    <section name="log4net" type="log4net.Config.Log4NetConfigurationSectionHandler,log4net" />
  </configSections>
  <log4net>
    <appender name="SMTPAppender" type="log4net.Appender.SMTPAppender">
      <authentication value="Basic" />
      <to value="xxx@xxx" />
      <from value="yyy@yyy" />
      <username value="user" />
      <password value="pass" />
      <subject value="ERROR" />
      <smtpHost value="host" />
      <port value="25" />
      <lossy value="true" />
      <evaluator type="log4net.Core.LevelEvaluator">
        <threshold value="WARN" />
      </evaluator>
      <layout type="log4net.Layout.PatternLayout">
        <conversionPattern value="%newline%date [%thread] %-5level %logger %newline %message%newline%newline%newline" />
      </layout>
    </appender>
    <root>
      <level value="INFO"></level>
    </root>
    <logger name="SMTPAppender">
      <level value="INFO"></level>
      <appender-ref ref="SMTPAppender"></appender-ref>
    </logger>
  </log4net>
</configuration>