Mobile

using System;
using System.Windows.Forms;
using System.Runtime.InteropServices;

namespace SomeNameSpace
{
 static class SingleInstance
 {
  [MTAThread]
  static void Main()
  {
   // Check if we have a duplicate instance of the program running
   if ( IsInstanceRunning() )
   {
    // Perhaps log the fact a duplicate program was shut down
    return;
   }

   /*
    * Continue with your normal program here
    */

   try
   {
    Application.Run( YourFormClass );
   }
   catch ( Exception e )
   {
    // Log an exception that caused the application to close here
    MessageBox.Show( "See log file for details.\r\nClosing this application.", "Fatal Application Error" );
   }
  }

#region OpenNETCF native interface to mutex generation (version 1.4 of the SDF)

  public const Int32 NATIVE_ERROR_ALREADY_EXISTS = 183;

#region P/Invoke Commands for Mutexes
  [DllImport( "coredll.dll", EntryPoint="CreateMutex", SetLastError=true )]
  public static extern IntPtr CreateMutex(
   IntPtr lpMutexAttributes,
   bool InitialOwner,
   string MutexName );

  [DllImport( "coredll.dll", EntryPoint="ReleaseMutex", SetLastError=true )]
  public static extern bool ReleaseMutex( IntPtr hMutex );
#endregion

  public static bool IsInstanceRunning()
  {
   IntPtr hMutex = CreateMutex( IntPtr.Zero, true, "ApplicationName" );
   if ( hMutex == IntPtr.Zero )
    throw new ApplicationException( "Failure creating mutex: "
     + Marshal.GetLastWin32Error().ToString( "X" ) );

   if ( Marshal.GetLastWin32Error() == NATIVE_ERROR_ALREADY_EXISTS )
    return true;
   else
    return false;
  }
#endregion
 }
}