Does WqlEventQuery contain a constructor with 1 argument?
I am trying to create a simple service in C# using VS2008 that creates a text file when the computer goes into sleep mode. My current code throws out the following error:
'SleepNotifierService.WqlEventQuery' does not contain a constructor that takes '1' arguments
Now I looked in the Object browser, and it looks like it does take in one argument. This is what the browser had to say:
public WqlEventQuery(string queryOrEventClassName)
Here is my code:
using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Diagnostics;
using System.Linq;
using System.ServiceProcess;
using System.Text;
using System.Management;
using System.IO;
namespace SleepNotifierService
{
public class WqlEventQuery : EventQuery { }
public partial class Service1 : ServiceBase
{
ManagementEventWatcher _watcher;
public Service1()
{
InitializeComponent();
}
protected override void OnStart(string[] args)
{
WqlEventQuery query = new WqlEventQuery("Win32_PowerManagementEvent");
_watcher = new ManagementEventWatcher(query);
_watcher.EventArrived += new EventArrivedEventHandler(watcher_EventArrived);
_watcher.Start();
}
protected override void OnStop()
{
_watcher.Stop();
}
void watcher_EventArrived(object sender, EventArrivedEventArgs e)
{
try
{
int eventType = Convert.ToInt32(e.NewEvent.Properties["EventType"].Value);
switch (eventType)
{
case 4:
Sleep();
break;
case 7:
Resume();
break;
}
}
catch (Exception ex)
{
//Log(ex.Message);
}
}
public void Sleep()
{
StreamWriter SW;
SW = File.CreateText("c:\\MyTextFile.txt开发者_运维技巧");
SW.WriteLine("Sleep mode initiated");
SW.Close();
}
public void Resume()
{
}
}
}
Am I interpreting that object browser wrong? I'm new to creating services and C#/.NET in general so it might be something trivial.
Appreciate any help,
Tomek
You're using wrong WqlEventQuery
. There's one defined in System.Management and it indeed has a one-argument constructor, but there's also your custom WqlEventQuery
class.
If you want to use .NET BCL's class, you'll have to fully qualify it:
var query = new System.Management.WqlEventQuery("Win32_PowerManagementEvent");
or even prefix it with global keyword:
var query = new global::System.Management.WqlEventQuery("Win32_PowerManagementEvent");
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