Single Instance Sample

   
  

<Application x:Class="SingleInstanceSample.App"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    StartupUri="Window1.xaml">
    <Application.Resources>
         
    </Application.Resources>
</Application>

//File:Window.xaml.cs
using System;
using System.Windows;
using System.Data;
using System.Xml;
using System.Configuration;
using System.Threading;
using System.Reflection;

namespace SingleInstanceSample {
  public partial class App : System.Windows.Application {
    Mutex mutex;
    protected override void OnStartup(StartupEventArgs e) {
      base.OnStartup(e);

      string mutexName = "MyCompanyName.MyAppName";
      bool createdNew;
      mutex = new Mutex(true, mutexName, out createdNew);

      if( !createdNew ) { Shutdown(); }
    }
  }
}