Program.cs

using System;
using System.Diagnostics;
using System.IO;
using System.Threading;
using System.Windows;
using System.Windows.Interop;
using TopmostApp.Interop;
using System.Windows.Media;
using VoicemeeterOsdProgram.Updater;

namespace VoicemeeterOsdProgram;

public class Program
{
    public const string Name = "VoicemeeterFancyOSD";
    public const string UniqueName = "AtgDev_VoicemeeterFancyOSD";

    public static App wpf_app;

    [STAThread]
    static void Main(string[] args) // if *Host.exe is launched "*Host.exe" may be the args[0]
    {
#if DEBUG
        //if (!Debugger.IsAttached) Debugger.Launch();
#endif
        AppDomain.CurrentDomain.UnhandledException += OnUnhandledException;
        AppDomain.CurrentDomain.ProcessExit += OnProcessExit;

        ArgsHandler.HandleSpecial(args);

        if (AppLifeManager.IsAlreadyRunning && (args.Length == 0))
        {
            args = [ArgsHandler.Args.OpenSettings];
        }

        Thread thread = new(() =>
        {
            ComponentDispatcher.ThreadFilterMessage += OnTerminationSignal;
            AppLifeManager.Start(args, () =>
            {
                RenderOptions.ProcessRenderMode = RenderMode.SoftwareOnly;
                System.Windows.Media.RenderOptions.ProcessRenderMode = RenderMode.SoftwareOnly;
                wpf_app = new();
                wpf_app.Run();
            });
        });

        //If you launch directly from the host bridge it won't be STA.
        thread.SetApartmentState(ApartmentState.STA);
        thread.Start();
    }

    private static void OnTerminationSignal(ref MSG msg, ref bool handled)
    {
        if ((msg.message == (int)WindowMessage.WM_CLOSE) || (msg.message == (int)WindowMessage.WM_QUIT))
        {
            Debug.WriteLine("TERMINATION SIGNAL RECEIVED");
            wpf_app?.Dispatcher.Invoke(() =>
            {
                wpf_app.Shutdown();
            });
        }
    }

    private static void OnUnhandledException(object sender, UnhandledExceptionEventArgs e)
    {
        Debug.WriteLine("UNHANDLED EXCEPTION");
        try
        {
            var ex = e.ExceptionObject as Exception;
            var path = AppDomain.CurrentDomain.BaseDirectory + @"\crashes";
            var filePath = path + @$"\crash {DateTime.Now:dd-MM-yyyy HH-mm-ss}.log";
            if (!Directory.Exists(path))
            {
                Directory.CreateDirectory(path);
            }
            using StreamWriter sr = new(filePath);
            sr.WriteLine($"{ex.GetType}\n{ex.Message}\n{ex.StackTrace}");
        }
        catch { }
    }

    private static void OnProcessExit(object sender, EventArgs e)
    {
        Debug.WriteLine("PROCESS EXIT");
    }
}