How to determine if a previous instance of my application is running?

Question

I have a console application in C# in which I run various arcane automation tasks. I am well aware that this should really be a Windows Service since it nee

Answer 1

Jeroen already answered this, but the best way by far is to use a Mutex... not by Process. Here's a fuller answer with code.

Mutex mutex;

try
{
   mutex = Mutex.OpenExisting("SINGLEINSTANCE");
   if (mutex!= null)
   {
      Console.WriteLine("Error : Only 1 instance of this application can run at a time");
      Application.Exit();
   }
}
catch (WaitHandleCannotBeOpenedException ex)
{
   mutex  = new Mutex(true, "SINGLEINSTANCE");
}

Also bear in mind that you need to run your Application in some sort of Try{} Finally{} block. Otherwise if you're application crashes without releasing the Mutex then you may not be able to restart it again later.