//引入命名空间
using System;
using System.Diagnostics;
using System.Threading;
              
class MySample{

    public static void Main(){
    
        // Create the source, if it does not already exist.
        if(!EventLog.SourceExists("MySource"))
        {
             //An event log source should not be created and immediately used.
             //There is a latency time to enable the source, it should be created
             //prior to executing the application that uses the source.
             //Execute this sample a second time to use the new source.
            EventLog.CreateEventSource("MySource", "MyNewLog");
            Console.WriteLine("CreatedEventSource");
            Console.WriteLine("Exiting, execute the application a second time to use the source.");
            // The source is created.  Exit the application to allow it to be registered.
            return;
        }
                
        // Create an EventLog instance and assign its source.
        EventLog myLog = new EventLog();
        myLog.Source = "MySource";
        
        // Write an informational entry to the event log.    
        myLog.WriteEntry("Writing to event log.");
    }
}

//引入命名空间
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.ServiceProcess;

public class Service1 : System.ServiceProcess.ServiceBase
{
    private System.Diagnostics.EventLog eventLog1;

    public Service1()
    {
        this.eventLog1 = new System.Diagnostics.EventLog();
        ((System.ComponentModel.ISupportInitialize)(this.eventLog1)).BeginInit();

        this.eventLog1.Log = "MyCustomLog";
        this.eventLog1.Source = "CustomEventService2";

        this.AutoLog = false;
        this.ServiceName = "CustomEventService";
        ((System.ComponentModel.ISupportInitialize)(this.eventLog1)).EndInit();
    }

    static void Main()
    {
        System.ServiceProcess.ServiceBase[] ServicesToRun;
        ServicesToRun = new System.ServiceProcess.ServiceBase[] { new Service1() };
        System.ServiceProcess.ServiceBase.Run(ServicesToRun);
    }

    protected override void OnStart(string[] args)
    {
        if ( !EventLog.SourceExists( eventLog1.Source ) )
        {
            EventLog.CreateEventSource( eventLog1.Source, eventLog1.Log );
        }
        eventLog1.WriteEntry( "Hello", EventLogEntryType.Information );
    }

    protected override void OnStop()
    {
        eventLog1.WriteEntry( "Goodbye", EventLogEntryType.Warning );
    }
}