Application.xaml.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Windows;
using Microsoft.Win32;

namespace Decomp
{
    public partial class Application
    {
#if DEBUG
        [System.Runtime.InteropServices.DllImport("Kernel32.dll")]
        [return: System.Runtime.InteropServices.MarshalAs(System.Runtime.InteropServices.UnmanagedType.Bool)]
        private static extern bool AllocConsole();

        [System.Runtime.InteropServices.DllImport("Kernel32.dll", CallingConvention = System.Runtime.InteropServices.CallingConvention.Winapi, CharSet = System.Runtime.InteropServices.CharSet.Unicode, EntryPoint = "CreateFileW", SetLastError = true)]
        private static extern IntPtr CreateFile(
            string lpFileName,
            uint dwDesiredAccess,
            uint dwShareMode,
            IntPtr lpSecurityAttributes,
            uint dwCreationDisposition,
            uint dwFlagsAndAttributes,
            IntPtr hTemplateFile
        );

        // ReSharper disable InconsistentNaming
        private const uint GENERIC_WRITE = 0x40000000;
        private const uint FILE_SHARE_WRITE = 0x2;
        private const uint OPEN_EXISTING = 0x3;
        // ReSharper restore InconsistentNaming
#endif

        private void ApplicationStartup(object sender, StartupEventArgs e)
        {
#if DEBUG
            AllocConsole();
            var hHandle = CreateFile("CONOUT$", GENERIC_WRITE, FILE_SHARE_WRITE, IntPtr.Zero, OPEN_EXISTING, 0, IntPtr.Zero);
            var streamWriter = new StreamWriter(new FileStream(new Microsoft.Win32.SafeHandles.SafeFileHandle(hHandle, true), FileAccess.Write)) { AutoFlush = true };
            Console.SetOut(streamWriter);
            Console.SetError(streamWriter);
#endif
            CommandLineArgs = Environment.GetCommandLineArgs().Skip(1).ToArray();

            var key = Registry.CurrentUser.OpenSubKey("Software\\WMD");
            if (key == null) return;
            var language = key.GetValue("Language") as string;
            if (language == "Russian" || language == "English") Language = language;
        }

        public static IList<string> CommandLineArgs { get; private set; }

        public static string StartupPath => Path.GetDirectoryName(System.Reflection.Assembly.GetEntryAssembly()?.Location);

        private static string _language = "";
        public static string Language
        {
            get => _language;
            set
            {
                _language = value;
                var newDict = new ResourceDictionary { Source = new Uri($"Languages/{value}.xaml", UriKind.Relative) };

                var oldDict = (from d in Current.Resources.MergedDictionaries where d.Source != null && d.Source.OriginalString.StartsWith("Languages/", StringComparison.OrdinalIgnoreCase) select d).First();

                if (oldDict != null)
                {
                    var i = Current.Resources.MergedDictionaries.IndexOf(oldDict);
                    Current.Resources.MergedDictionaries.Remove(oldDict);
                    Current.Resources.MergedDictionaries.Insert(i, newDict);
                }
                else
                {
                    Current.Resources.MergedDictionaries.Add(newDict);
                }
            }
        }

        public static string GetResource(string s) => (string)Current.FindResource(s);
    }
}