windows服務中的定時器timer的使用

大家在使用c#寫windows服務時，網上很多例子說，使用工具箱中組件中的定時器就可以，但實際上該定時器並不管用，具體原因，微軟自稱是Framework的bug。

無論是windows窗體中timer還是組件中的timer都是繼承自System.Windows.Form.Timer,並不是我們需要的System.Timers ，繼承自System.Timers 的timer只有手動創建。

public WindowsServiceDemo()

        {

            InitializeComponent();

            System.Timers.Timer t = new System.Timers.Timer(1000);//實例化Timer類，設置間隔時間爲10000毫秒； 

            t.Elapsed += new System.Timers.ElapsedEventHandler(TimeElapse);//到達時間的時候執行事件； 

            t.AutoReset = true;//設置是執行一次（false）還是一直執行(true)； 

            t.Enabled = true;//是否執行System.Timers.Timer.Elapsed事件；

        }

public void TimeElapse(object source, System.Timers.ElapsedEventArgs e)

        {

            //EventLog log = new EventLog();

            //log.Source = "我的應用程序";

            //log.WriteEntry("1秒調用一次", EventLogEntryType.Information);

            FileStream fs = new FileStream(@"d:/timetick.txt", FileMode.OpenOrCreate, FileAccess.Write);

            StreamWriter m_streamWriter = new StreamWriter(fs);

            m_streamWriter.BaseStream.Seek(0, SeekOrigin.End);

            m_streamWriter.WriteLine("過了一秒 " + DateTime.Now.ToString() + "/n");

            m_streamWriter.Flush();

            m_streamWriter.Close();

            fs.Close();

        }

 

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雙方System.Timers.Timer和System.Threading.Timer將工作服務。

該定時器要避免的是System.Web.UI.Timer和System.Windows.Forms.Timer這是ASP應用程序和WinForms分別。 使用這些將導致服務加載的額外組裝這不是真正的應用程序，您需要的是建築類型。

使用類似下面的例子System.Timers.Timer另外，請確保您使用一個類級變量，以防止垃圾收集）：

using System; 
using System.Timers; 
public class Timer1 
{ 
    private static System.Timers.Timer aTimer; 
    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 a ten second interval. 
        aTimer = new System.Timers.Timer(10000); 
        // Hook up the Elapsed event for the timer. 
        aTimer.Elapsed += new ElapsedEventHandler(OnTimedEvent); 
        // Set the Interval to 2 seconds (2000 milliseconds). 
        aTimer.Interval = 2000; 
        aTimer.Enabled = true; 
        Console.WriteLine("Press the Enter key to exit the program."); 
        Console.ReadLine(); 
        // 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); 
    } 
    // Specify what you want to happen when the Elapsed event is  
    // raised. 
    private static void OnTimedEvent(object source, ElapsedEventArgs e) 
    { 
        Console.WriteLine("The Elapsed event was raised at {0}", e.SignalTime); 
    } 
} 
/* This code example produces output similar to the following: 
Press the Enter key to exit the program. 
The Elapsed event was raised at 5/20/2007 8:42:27 PM 
The Elapsed event was raised at 5/20/2007 8:42:29 PM 
The Elapsed event was raised at 5/20/2007 8:42:31 PM 
... 
 */ 

如果您選擇System.Threading.Timer可以使用如下：

using System; 
using System.Threading; 
class TimerExample 
{ 
    static void Main() 
    { 
        AutoResetEvent autoEvent     = new AutoResetEvent(false); 
        StatusChecker  statusChecker = new StatusChecker(10); 
        // Create the delegate that invokes methods for the timer. 
        TimerCallback timerDelegate =  
            new TimerCallback(statusChecker.CheckStatus); 
        // Create a timer that signals the delegate to invoke  
        // CheckStatus after one second, and every 1/4 second  
        // thereafter. 
        Console.WriteLine("{0} Creating timer./n",  
            DateTime.Now.ToString("h:mm:ss.fff")); 
        Timer stateTimer =  
                new Timer(timerDelegate, autoEvent, 1000, 250); 
        // When autoEvent signals, change the period to every  
        // 1/2 second. 
        autoEvent.WaitOne(5000, false); 
        stateTimer.Change(0, 500); 
        Console.WriteLine("/nChanging period./n"); 
        // When autoEvent signals the second time, dispose of  
        // the timer. 
        autoEvent.WaitOne(5000, false); 
        stateTimer.Dispose(); 
        Console.WriteLine("/nDestroying timer."); 
    } 
} 
class StatusChecker 
{ 
    int invokeCount, maxCount; 
    public StatusChecker(int count) 
    { 
        invokeCount  = 0; 
        maxCount = count; 
    } 
    // This method is called by the timer delegate. 
    public void CheckStatus(Object stateInfo) 
    { 
        AutoResetEvent autoEvent = (AutoResetEvent)stateInfo; 
        Console.WriteLine("{0} Checking status {1,2}.",  
            DateTime.Now.ToString("h:mm:ss.fff"),  
            (++invokeCount).ToString()); 
        if(invokeCount == maxCount) 
        { 
            // Reset the counter and signal Main. 
            invokeCount  = 0; 
            autoEvent.Set(); 
        } 
    } 
} 

這兩個例子來自MSDN的網頁。