moodmeter/AffdexMe/App.cs

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Data;
using System.Linq;
using System.Threading.Tasks;
using System.Windows;

using Microsoft.VisualBasic.ApplicationServices;

namespace AffdexMe
{
    /// <summary>
    /// Interaction logic for App.xaml
    /// </summary>
    public partial class App : Application
    {
    }


    /// <summary>
    /// From reference source: https://msdn.microsoft.com/en-us/library/vstudio/ms771662(v=vs.90).aspx
    /// </summary>
    public class EntryPoint
    {
        [STAThread]
        public static void Main(string[] args)
        {
            SingleInstanceManager manager = new SingleInstanceManager();
            manager.Run(args);
        }
    }

    // Using VB bits to detect single instances and process accordingly:
    //  * OnStartup is fired when the first instance loads
    //  * OnStartupNextInstance is fired when the application is re-run again
    //    NOTE: it is redirected to this instance thanks to IsSingleInstance
    public class SingleInstanceManager : WindowsFormsApplicationBase
    {
        SingleInstanceApplication app;

        public SingleInstanceManager()
        {
            this.IsSingleInstance = true;
        }


        protected override bool OnStartup(Microsoft.VisualBasic.ApplicationServices.StartupEventArgs e)
        {
            // First time app is launched
            app = new SingleInstanceApplication();
            app.Run();
            return false;
        }

        protected override void OnStartupNextInstance(StartupNextInstanceEventArgs eventArgs)
        {
            // Subsequent launches
            base.OnStartupNextInstance(eventArgs);
            app.Activate();
        }
    }

    public class SingleInstanceApplication : Application
    {

        protected override void OnStartup(System.Windows.StartupEventArgs e)
        {
            base.OnStartup(e);

            // Create and show the application's main window
            MainWindow window = new MainWindow();
            window.Show();
        }

        public void Activate()
        {
            // Reactivate application's main window
            this.MainWindow.Activate();
        }
    }
}