Run one instance from the application

Question

I have a windows application (C#) and i need to configure it to run one instance from the application at the time , It means that one user clicked the .exe file and the appl

Answer 1

We had exactly the same problem. We tried the process approach, but this fails, if the user has no right to read information about other processes, i.e. non-admins. So we implemented the solution below.

Basically we try to open a file for exclusive reading. If this fails (because anohter instance has already done this), we get an exception and can quit the app.

        bool haveLock = false;
        try
        {
            lockStream = new System.IO.FileStream(pathToTempFile,System.IO.FileMode.Create,System.IO.FileAccess.ReadWrite,System.IO.FileShare.None);
            haveLock = true;
        }
        catch(Exception)
        {
            System.Console.WriteLine("Failed to acquire lock. ");
        }
        if(!haveLock)
        {
            Inka.Controls.Dialoge.InkaInfoBox diag = new Inka.Controls.Dialoge.InkaInfoBox("App has been started already");
            diag.Size = new Size(diag.Size.Width + 40, diag.Size.Height + 20);
            diag.ShowDialog();
            Application.Exit();
        }