Creating a Single Instance of your Application

[Paul M]

This will only allow one instance of your application, i use this code for a couple of my programs/services...

Make sure you maker a reference to the System.Management class

static void Main()
        {
            Application.EnableVisualStyles();
            Application.SetCompatibleTextRenderingDefault(false);
            
            int count = CheckForRunningInstances();
 
            if (count <= 1)
            {
                Application.Run(new Form1());
            }
            else
            {
                System.Windows.Forms.MessageBox.Show("Another instance of this program is already running.  Two instances cannot run at the same time", "Already running", MessageBoxButtons.OK, MessageBoxIcon.Exclamation);
                Application.Exit();
            }
 
        }
        private static int CheckForRunningInstances()
        {
 
            string[] parts = System.Reflection.Assembly.GetExecutingAssembly().Location.Split("\\".ToCharArray());
            string appName = parts[parts.Length - 1];
 
            string query = "select name from CIM_Process where name = '" + appName + "'";
 
            System.Management.ManagementObjectSearcher searcher = new System.Management.ManagementObjectSearcher(query);
 
            int hInstCount = 0;
 
            foreach (System.Management.ManagementObject item in searcher.Get())
            {
                hInstCount++;
                if (hInstCount > 1) break;
            }
            return hInstCount;
        }