xmleventlogwritter.cs.txt

蓝牙通讯

using System;
using System.Xml;
using System.IO;
using System.Collections;
using OpenNETCF;

namespace OpenNETCF.Diagnostics
{
	/// <summary>
	/// Implements writting to the event log using XML
	/// </summary>
	public class XMLEventLogWritter:IEventLogWritter
	{

		public event EntryWrittenEventHandler EntryWritten;
		public event EventHandler EventLogCollectionUpdated;

		private string source="";
		private string log="";
		private string logFileName="";		
		private string logPath="";
		private string logDisplayName="";
		private EventLogEntryCollection eventLogEntryCollection = new EventLogEntryCollection();
		private ArrayList eventLogCollection = null;

		/// <summary>
		/// The Xml document representing the log
		/// </summary>
		private XmlDocument xmlLog=null;
		/// <summary>
		/// The current eventlog node which contains all Log nodes
		/// </summary>
		private XmlNode nodeEventLog = null;
		/// <summary>
		/// The current log node that is being written to
		/// </summary>
		private XmlNode nodeLog = null;
		/// <summary>
		/// The default Xml for a new log
		/// </summary>
		private readonly string EVENTLOG_ROOT = "<eventLog></eventLog>";

		internal XMLEventLogWritter(string log, string source, string logPath, string logFileName) 
		{
			this.log = log;
			this.source = source;
			this.logPath = logPath;
			this.logFileName = logFileName;
			this.InitializeLogFile();
		}
        		
		#region Private Methods
		/// <summary>
		/// Creates the XML document to store the event logs
		/// </summary>
		private void InitializeLogFile()
		{
			//Create the log file
			this.CreateLogFile();

			//Load the nodes
			this.LoadNodes();

			//Save the file
			this.SaveLogFile();

			//Load the eventLogEntryColelction
			this.LoadEventLogEntryCollection();

		}

		/// <summary>
		/// Loads the eventlog collection
		/// </summary>
		private void LoadEventLogCollection()
		{
			XmlNodeList list = this.xmlLog.GetElementsByTagName("log");
			this.eventLogCollection = new ArrayList();
			foreach(XmlNode node in list)
			{
				string log = this.NodeAttributeValue(node,"name");
				if(log.Length>0)
				{
					eventLogCollection.Add(new EventLog(log,"",this.logPath,this.logFileName, EventLogWritterType.XML));
				}
			}
		}

		/// <summary>
		/// Creates a log file on the system
		/// </summary>
		private void CreateLogFile()
		{
			//Create a new log file
			this.xmlLog = new XmlDocument();

			//Check to see if the file exists
			if(File.Exists(this.logPath+this.logFileName))
			{
				//The file is available so load it into the XML
				try
				{
					this.xmlLog.Load("file://"+this.logPath+this.logFileName);
				}
				catch(Exception e)
				{
					throw new Exception("Unable to open log file as XML!!",e);
				}
			}
			else
			{
				//The file does not exist so load the default XML
				this.xmlLog.LoadXml(this.EVENTLOG_ROOT);
			}
		}

		/// <summary>
		/// Loads the source, log and EventLog nodes
		/// </summary>
		private void LoadNodes()
		{
			//Get the event Log node
			this.nodeEventLog = this.xmlLog.GetElementsByTagName("eventLog")[0];

			//Get the current log node
			this.nodeLog = this.EventLogNode(this.log);
			if(this.nodeLog==null)
			{
				//Create the log node
				this.nodeLog = this.CreateLogNode(this.log);			
			}

			//Set the log display name
			this.logDisplayName = this.NodeAttributeValue(nodeLog,"logDisplayName");
		}
		

		/// <summary>
		/// Loads the eventlog entry collection
		/// </summary>
		private void LoadEventLogEntryCollection()
		{
			//This is only called when the log is changed and when the class is instantiated so it's pretty safe
			//to re-init the collection
			this.eventLogEntryCollection = new EventLogEntryCollection();
			string[] attributes = new string[]{"machineName","userName","timeGenerated",
												  "source","message","eventLogEntryType",
												  "eventID","category","rawData","id","timeWritten","index"};

			//Get all the eventLog nodes
			foreach(XmlNode node in this.nodeLog.ChildNodes)
			{
				string machineName = node.Attributes.GetNamedItem(attributes[0]).Value;
				string userName = node.Attributes.GetNamedItem(attributes[1]).Value;
				DateTime timeGenerated = DateTime.Parse(node.Attributes.GetNamedItem(attributes[2]).Value);
				string source = node.Attributes.GetNamedItem(attributes[3]).Value;
				string message = node.Attributes.GetNamedItem(attributes[4]).Value;
				EventLogEntryType type = (EventLogEntryType)Int32.Parse(node.Attributes.GetNamedItem(attributes[5]).Value);
				int eventID = Int32.Parse(node.Attributes.GetNamedItem(attributes[6]).Value);
				short category = Int16.Parse(node.Attributes.GetNamedItem(attributes[7]).Value);
				byte[] rawData = System.Text.Encoding.Unicode.GetBytes(node.Attributes.GetNamedItem(attributes[8]).Value);
				string id = node.Attributes.GetNamedItem(attributes[9]).Value;
				DateTime timeWritten = DateTime.Parse(node.Attributes.GetNamedItem(attributes[10]).Value);
				int index = Int32.Parse(node.Attributes.GetNamedItem(attributes[11]).Value);
			
				//Add to the collection
				EventLogEntry eventLogEntry = new EventLogEntry(category,rawData,type,eventID,index,machineName,message,source,timeGenerated,timeWritten,userName,id);
				this.eventLogEntryCollection.Add(eventLogEntry);
			}
		}
		/// <summary>
		/// Create the log node and adds it to the nodeEventLog
		/// </summary>
		private XmlNode CreateLogNode(string logName)
		{
			XmlNode newNode = this.xmlLog.CreateNode(XmlNodeType.Element,"log","");
			XmlAttribute att = this.xmlLog.CreateAttribute("name");
			att.Value = this.log;
			newNode.Attributes.Append(att);
			att = this.xmlLog.CreateAttribute("logDisplayName");
			att.Value = this.logDisplayName;
			newNode.Attributes.Append(att);
			this.nodeEventLog.AppendChild(newNode);
			return newNode;
		}

		/// <summary>
		/// Retrieves and event log node by logName
		/// </summary>
		/// <param name="logName">The name of the log node</param>
		/// <returns>The XmlNode containing the log items or null if not found</returns>
		private XmlNode EventLogNode(string logName)
		{
			XmlNodeList list = this.xmlLog.GetElementsByTagName("log");
			foreach(XmlNode node in list)
			{
				XmlAttribute att = (XmlAttribute)node.Attributes.GetNamedItem("name");
				if(att!=null)
					if(att.Value == logName)
						return node;
			}

			//Return null;
			return null;
		}

		/// <summary>
		/// Changes an attribute in the specified node
		/// </summary>
		private void NodeAttributeValue(XmlNode node, string attributeName, string newAttributeValue)
		{
			XmlAttribute att = (XmlAttribute)node.Attributes.GetNamedItem(attributeName);
			if(att!=null)
			{
				att.Value = newAttributeValue;		
				this.SaveLogFile();
			}	
			else
				throw new Exception("Attribute " + attributeName + " not found in node \"" + node.Name + "\"");
		}

		/// <summary>
		/// Retreives the attribute in the specified node
		/// </summary>
		/// <param name="node"></param>
		/// <param name="attName"></param>
		/// <returns>The value of the attribute or null if not found</returns>
		private string NodeAttributeValue(XmlNode node, string attributeName)
		{
			XmlAttribute att = (XmlAttribute)node.Attributes.GetNamedItem(attributeName);
			if(att!=null)
				return att.Value;
			else
				return "";
		}

		/// <summary>
		/// Saves the logfile
		/// </summary>
		private void SaveLogFile()
		{
			this.xmlLog.Save(this.LogPath+this.LogFileName);
		}	
	
		/// <summary>
		/// Writes an entry to the log file
		/// </summary>
		/// <param name="source"></param>
		/// <param name="message"></param>
		/// <param name="type"></param>
		/// <param name="eventID"></param>
		/// <param name="category"></param>
		/// <param name="rawData"></param>
		private void WriteEntryToLog(string source, string message, EventLogEntryType type, int eventID, short category, byte[] rawData)
		{
			if(this.nodeLog!=null)
			{
				//Create the event node
				XmlNode nodeEventLog = this.xmlLog.CreateNode(XmlNodeType.Element,"eventLogEntry","");

				//Now create all the attributes
				DateTime timeGenerated = DateTime.Now;
				string machineName = ".";
				string userName = "";

				//Machine Name
				XmlAttribute att = this.xmlLog.CreateAttribute("machineName");
				att.Value = machineName;
				nodeEventLog.Attributes.Append(att);

				//user name
				att = this.xmlLog.CreateAttribute("userName");
				att.Value = userName;
				nodeEventLog.Attributes.Append(att);

				//DateTime generate
				att = this.xmlLog.CreateAttribute("timeGenerated");
				att.Value = DateTime.Now.ToString();
				nodeEventLog.Attributes.Append(att);

				//source
				att = this.xmlLog.CreateAttribute("source");
				att.Value = source;
				nodeEventLog.Attributes.Append(att);

				//message
				att = this.xmlLog.CreateAttribute("message");
				att.Value = message;
				nodeEventLog.Attributes.Append(att);

				//EventLogEntryType
				att = this.xmlLog.CreateAttribute("eventLogEntryType");
				att.Value = ((int)type).ToString();
				nodeEventLog.Attributes.Append(att);

				//EventID
				att = this.xmlLog.CreateAttribute("eventID");
				att.Value = eventID.ToString();
				nodeEventLog.Attributes.Append(att);

				//categor
				att = this.xmlLog.CreateAttribute("category");