How can I prevent launching my app multiple times?

Question

I deployed my C# WinForms application using ClickOnce installation. Everything works fine with it (after a lot of work) :), but now I'm facing a problem:

Whenever I click on the application shortcut in the Start menu, a new instance starts. I need to avoid this.

What can I do to prevent multiple launches?

Answer 1

At program startup check if same process is already running:

using System.Diagnostics;

static void Main(string[] args)
{
   String thisprocessname = Process.GetCurrentProcess().ProcessName;

   if (Process.GetProcesses().Count(p => p.ProcessName == thisprocessname) > 1)
      return;           
}