EventLog.CreateEventSource is not creating a custom log

Question

I have some code like this:

EventLog.CreateEventSource("myApp", "myAppLog");
EventLog.WriteEntry("myApp", "Test log message", EventLogEntryType.Error);

Now, unless I'm missing something having read MSDN, this should cause a new log 'myAppLog' to be created in the event viewer, and an entry should be added to that new log with the source name 'myApp'. But, I can't get the new log to be created. This always just writes an error log message to the Application log, with the source 'myApp' - 'myAppLog' is nowhere to be seen. What am I doing wrong? I am logged in as an Administrator.

Answer 1

Is it possible that you already used the source "myApp" when writing to the standard Application log? If so according to MSDN:

If a source has already been mapped to a log and you remap it to a new log, you must restart the computer for the changes to take effect.

http://msdn.microsoft.com/en-us/library/2awhba7a.aspx (about half way down the page)

Answer 2

I have just written a little code to help me out of this. source registered in another log issue which I have encountered and don't want to manually have to remove sources from logs. What I decided to do was check if the source exists, if it does check that its linked to the correct log, if it isn't delete the source, now that it doesn't exist or f it never did create the Log brand new.

protected const string EventLogName = "MyLog";

private static bool CheckSourceExists(string source) {
  if (EventLog.SourceExists(source)) {
    EventLog evLog = new EventLog {Source = source};
    if (evLog.Log != EventLogName) {
      EventLog.DeleteEventSource(source);
    }
  }

  if (!EventLog.SourceExists(source)) {
    EventLog.CreateEventSource(source, EventLogName);
    EventLog.WriteEntry(source, String.Format("Event Log Created '{0}'/'{1}'", EventLogName, source), EventLogEntryType.Information);
  }

  return EventLog.SourceExists(source);
}

public static void WriteEventToMyLog(string source, string text, EventLogEntryType type) {      
  if (CheckSourceExists(source)) {          
      EventLog.WriteEntry(source, text, type);          
  }
}

Hopefully it helps :)