How to check if a WPF application is already running? [duplicate]

Answer 1

public partial class App
    {
        private const string Guid = "250C5597-BA73-40DF-B2CF-DD644F044834";
        static readonly Mutex Mutex = new Mutex(true, "{" + Guid + "}");

        public App()
        {

            if (!Mutex.WaitOne(TimeSpan.Zero, true))
            {
                //already an instance running
                Application.Current.Shutdown();
            }
            else
            {
                //no instance running
            }
        }
    }