时间流逝或整数达到指定限制 - 怎么办？ (C#)

Question

我正在运行一个 C# 程序（控制台应用程序，很快将转换为 Windows 服务），我需要能够向管理员发送有关服务中错误的电子邮件，但我需要它不要针对每个错误向我们发送电子邮件，如果最近几分钟的错误数量超过 4-5 个，因此它只会发送一封电子邮件，说明存在多个错误。

我知道我会以某种形式使用计时器，但是任何人都可以提供更具体的建议吗？我将非常感激

Answer 1

修改自MSDN。请注意有关 Timer 对象 aTimer 声明和清理的注释。

using System;
using System.Timers;
using System.Threading;

public class Timer2
{
    private static System.Timers.Timer aTimer;
    private static List<string> errors = new List<string>();
    private static readonly int interval = 300000;  // 5 minutes at present
    private static readonly int trigger = 10;       // send msg if > 10 errors

    // Message processing - error detection
    public static void processMessage(Message message)
    {
      // do the work here
      // then check error
      if (message.HasError)
      {
        // add error to pending list
        lock (errors)
        {
          string newErrorData = "got another one!";
          errors.Add(newErrorData);
          ++trigger;
        }
      }
    }

    public static void Main()
    {
        // Normally, the timer is declared at the class level,
        // so that it stays in scope as long as it is needed.
        // If the timer is declared in a long-running method,  
        // KeepAlive must be used to prevent the JIT compiler 
        // from allowing aggressive garbage collection to occur 
        // before the method ends. (See end of method.)
        //System.Timers.Timer aTimer;

        // Create a timer with specified interval.
        aTimer = new System.Timers.Timer(interval);

        // Hook up the event handler for the Elapsed event.
        aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent);
        aTimer.Enabled = true;

        // Kick off message handling - don't forget to clean up the timer when 
        // you wish to exit
        while (moreMessages)
        {
           Message message = getNextmessage();
           ProcessMessage(message);
        }
        // cleanup here when messages are drained
        // If the timer is declared in a long-running method, use
        // KeepAlive to prevent garbage collection from occurring
        // before the method ends.
        //GC.KeepAlive(aTimer);        }

    private static void OnTimedEvent(object source, ElapsedEventArgs e) 
    {
        object errorEmail = null;
        lock (errors)
        {
            if (errors.Count > trigger)
            {
               // init message to contain errors here
               errorEmail = new ErrorEmail();
               foreach (string err in errors)
               {
                  // add error info to message
               } 
               errors.Clear();
               trigger = 0;
            }
        }
        if (errorEmail != null)
        {
          // send message outside the lock
          Send(errorEmail);
        }
    }
}

Answer 2

如果您使用数据库跟踪发送的每封电子邮件，则可以随时轮询数据库，以查看在给定时间段内针对给定错误您看到了多少封电子邮件等。在我参与过的几个项目中，电子邮件是一个很重要的问题。要求，记录发送的电子邮件始终是一个姐妹要求，从而为您的问题创建解决方案。

Answer 3

使用将错误保存在列表中，然后使用 System.Threading.Timer< /a>.

传递一个封装 SendEmail 方法的委托。