WMI Notification Provider

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Introduction

Logging in custom application is mandatory, tracing business process execution, trouble shooting and detecting errors, etc.....

But what if a critical error occured, and needs a quick action, or how would you know that something went wrong.

WMI events: you can raise WMI events to be captured by an application to act quickly (MOM for example), send an E-mail, send SMS etc...... 

Background

WMI:Windows Management Instrumentation (WMI) is a set of extensions to the Windows Driver Model that provides an operating system interface through whichinstrumented components provide information and notification. WMI is Microsoft's implementation of the Web-Based Enterprise Management (WBEM) and Common Information Model (CIM) standards from the Distributed Management Task Force (DMTF).  

Using the code 

  this class is a representation for the Message that is gonna be publish. 

	[InstrumentationClass(InstrumentationType.Instance)]
	public class InfoMessage
	{
		public string Message;
        public string ApplicationName;
		public string Guid;
		public int Type;

		// return an empty info message
		public static InfoMessage EmptyMessage()
		{
			return new InfoMessage();
		}
	} 

 /// <summary>
	/// this is a event this instrumented application can fire
	/// </summary>
	public class EventDetails : BaseEvent
	{
		public string Message;
        public string ApplicationName;
		public string Guid;
		public int Type;
	}

 /// <summary>
	/// this class provides static methods to publish messages to WMI
	/// </summary>
	public class InstrumentationProvider
	{
		/// <summary>
		/// private constructor so no instance of the class can be created
		/// </summary>
		private InstrumentationProvider()
		{
		}

		/// <summary>
		/// publishes a message to the WMI repository
		/// </summary>
		/// <param name="MessageText">the message text</param>
		/// <param name="Type">the message type</param>
		public static InfoMessage PublishMessage(string MessageText,string applicationName,MessageType Type)
		{
			// create a new message
			InfoMessage Message = new InfoMessage();

			// set its properties
			Message.Message = MessageText;
            Message.ApplicationName = applicationName;
			Message.Guid = Guid.NewGuid().ToString();
			Message.Type = (int)Type;

			try
			{
				// publishes the message to the WMI repository
				Instrumentation.Publish(Message);
			}

			// we have not been able to publish the message so we return an empty message
			catch (ManagementException)
			{
				return InfoMessage.EmptyMessage();
			}

			// return the message
			return Message;
		}

		/// <summary>
		/// revoke a previously published message from the WMI repository
		/// </summary>
		/// <param name="Message">the message to revoke</param>
		public static void RevokeMessage(InfoMessage Message)
		{
			Instrumentation.Revoke(Message);
		}

		/// <summary>
		/// fires a WMI event
		/// </summary>
		/// <param name="Message">the event message</param>
		/// <param name="Type">the event type</param>
		/// <returns>has event been fired successfully</returns>
		public static bool FireEvent(string Message,string applicationName, EventType Type)
		{
			// create a new event
			EventDetails Details = new EventDetails();

			// set the event details
			Details.Message = Message;
            Details.ApplicationName = applicationName;
			Details.Guid = Guid.NewGuid().ToString();
			Details.Type = (int)Type;

			try
			{
				// fire the event so consumers can consume it
				Details.Fire();
			}

			// catch any exception and return false
			catch (ManagementException)
			{
				return false;
			}

			// we successfully fired the event
			return true;
		}
	} 

 [RunInstaller(true)]
	public class InstrumentationProviderInstaller : DefaultManagementProjectInstaller
	{ 
	} 

Points of Interest

System.Management.Instrumentation; 

History 

V1.0 

This article, along with any associated source code and files, is licensed under The Code Project Open License (CPOL)