Check for Single-Instance

by vckicks on Aug 25th, 2008

A simple way to check if the current C# program is the only instance of itself running.

private bool IsSingleInstance()
{
     foreach (Process process in Process.GetProcesses())
     {
          if (process.MainWindowTitle == this.Text)
               return false;
     }
     return true;
}

Comments on this Code Snippet

Permalink

Nov 2nd, 2009

Re: Check for Single-Instance

this give error....
In foreach line (in process)
always mention namespace which is required and that place where code to be paste

ashishkumar008

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45 posts
since Nov 2009

Permalink

Nov 2nd, 2009

Re: Check for Single-Instance

Simple, yes... but not something I'd allow into production code. See these links for some discussion.

Here's an alternative... first, a method to try to create a mutex unique to the application:

C# Syntax (Toggle Plain Text)
private Mutex GetSingleInstanceMutex()
{
    bool createdNewMutex;
 
    Mutex mutex = new Mutex(false, @"Global\" + SomethingUnique, out createdNewMutex);
 
    if (!createdNewMutex)
    {
        mutex = null;
    }
 
    return mutex;
}
private Mutex GetSingleInstanceMutex()
{
    bool createdNewMutex;

    Mutex mutex = new Mutex(false, @"Global\" + SomethingUnique, out createdNewMutex);

    if (!createdNewMutex)
    {
        mutex = null;
    }

    return mutex;
}

SomethingUnique should be something unique to the application, for example, the assembly GUID.

Here's how you'd use the method:

C# Syntax (Toggle Plain Text)
using (Mutex mutex = GetSingleInstanceMutex())
{
    if (mutex != null)
    {
        // This is the only running instance; go ahead and run the application.
    }
    else
    {
        // Another instance is running; notify user and quit.
    }
}
using (Mutex mutex = GetSingleInstanceMutex())
{
    if (mutex != null)
    {
        // This is the only running instance; go ahead and run the application.
    }
    else
    {
        // Another instance is running; notify user and quit.
    }
}

gusano79

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Offline

476 posts
since May 2004

Permalink

Nov 3rd, 2009

Re: Check for Single-Instance

Request:-
i want to use flash file in webbrowser like other resources like picture
i do not want to use full path (c:\programfile\).
can u post full c# code
please

ashishkumar008

Light Poster

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45 posts
since Nov 2009

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