C# : how to - single instance application that accepts new parameters?

Question

I'm creating a (C#) program that downloads binaries using NZB files, there may only be one instance of my application running at any time.

So when a user doubleclicks an .nzb-file and my program is not running, it should start and process it (easy, file registration). Now if my program is already running, I do NOT want to launch a second instance - I want the already-running instance to pick up the specified file.

Making my app single-instance can be done using the Visual Basic DLL with the .IsSingleInstance trick, but I don't want to go there.

The right way seems to be to use a mutex to ensure my app is single-instance, but now I'm stuck on how to pass the specified parameter (the .nzb file) to the already-running instance.

Help would be appreciated ! :-)

Answer 1

Try this: Your main program creates a named pipe or other interprocess communication facility and listens on it. You create a separate small program that, when run with an NZB file as a parameter, opens the pipe, feeds the file info into it, and exits. Your main program then processes the new file and downloads it.