C#: GUI to display realtime messages from Windows Service
I've written a C# windows service which can write messages to a custom EventLog or to any number of files. These messages are all marked with some priority (so, for example, only ERRORs and WARNINGs get stored in the EventLog, but if desired a lot more can be stored to a file).
What I'd like to do now is create a GUI that can listen for these messages and display them in real-time. Allowing a user to watch the current messages (at whatever their desired priority level), without the need to store everything to a file. I assume this is a separate program with some form of hook into the service, but I'm unsure of where to start.
This is my first real windows service, so I seem to be missing some keywords for finding out how to do this... Are there any code samples, tutorials, references, etc. for how to do something like this?
UPDATE
A lot of helpful answers, I love it when there's many ways to solve a problem! I think I'm going to implement a self-hosting WCF based solution. I'm still very light on the details as I'm trying to learn about WCF (I believe it will prove quite useful for me in other projects)... but thus far, I've found the videos here to be the most helpful as an intro how-to.
Answer
What you can do is have the windows service have way of registering for an event (you can do this through using Windows Communication Foundation). When your error comes up, it fires that event, and your winforms app will be notified. It's called a duplex contract:
http://social.msdn.microsoft.com/Forums/en-US/wcf/thread/0eb69998-0388-4731-913e-fb205528d374/
http://msdn.microsoft.com/en-us/library/ms731184.aspx
Actually the really cool thing is that you can have multiple applications listening this way too. So you can display it on screen, and have another application log it etc. without the two external apps knowing anything about each other.