Working with keyboard layouts on Windows in C# (ActivateKeyboardLayout/GetKeyboardLayout/GetKeyboardLayoutList)

KeyboardLayouts.cs

namespace Vurdalakov
{
    using Microsoft.Win32;
    using System;
    using System.Collections.Generic;
    using System.Diagnostics;
    using System.Globalization;
    using System.Runtime.InteropServices;

    public class KeyboardLayout
    {
        public UInt32 Id { get; }

        public UInt16 LanguageId { get; }
        public UInt16 KeyboardId { get; }

        public String LanguageName { get; }
        public String KeyboardName { get; }

        internal KeyboardLayout(UInt32 id, UInt16 languageId, UInt16 keyboardId, String languageName, String keyboardName)
        {
            this.Id = id;
            this.LanguageId = languageId;
            this.KeyboardId = keyboardId;
            this.LanguageName = languageName;
            this.KeyboardName = keyboardName;
        }
    }

    public static class KeyboardLayouts
    {
        public static KeyboardLayout GetThreadKeyboardLayout(Int32 threadId = 0)
        {
            var keyboardLayoutId = (UInt32)GetKeyboardLayout((UInt32)threadId);

            return CreateKeyboardLayout(keyboardLayoutId);
        }

        public static KeyboardLayout GetProcessKeyboardLayout(Int32 processId = 0)
        {
            var threadId = GetProcessMainThreadId(processId);
            return GetThreadKeyboardLayout(threadId);
        }

        public static UInt32 SetThreadKeyboardLayout(UInt32 keyboardLayoutId)
        {
            return SetKeyboardLayout(keyboardLayoutId, 0);
        }

        public static UInt32 SetProcessKeyboardLayout(UInt32 keyboardLayoutId)
        {
            return SetKeyboardLayout(keyboardLayoutId, KLF_SETFORPROCESS);
        }

        public static KeyboardLayout[] GetSystemKeyboardLayouts()
        {
            var keyboardLayouts = new List<KeyboardLayout>();

            var count = GetKeyboardLayoutList(0, null);
            var keyboardLayoutIds = new IntPtr[count];
            GetKeyboardLayoutList(keyboardLayoutIds.Length, keyboardLayoutIds);

            foreach (var keyboardLayoutId in keyboardLayoutIds)
            {
                var keyboardLayout = CreateKeyboardLayout((UInt32)keyboardLayoutId);
                keyboardLayouts.Add(keyboardLayout);
            }

            return keyboardLayouts.ToArray();
        }

        private static Int32 GetProcessMainThreadId(Int32 processId = 0)
        {
            var process = 0 == processId ? Process.GetCurrentProcess() : Process.GetProcessById(processId);
            return process.Threads[0].Id;
        }

        private static KeyboardLayout CreateKeyboardLayout(UInt32 keyboardLayoutId)
        {
            var languageId = (UInt16)(keyboardLayoutId & 0xFFFF);
            var keyboardId = (UInt16)(keyboardLayoutId >> 16);

            return new KeyboardLayout(keyboardLayoutId, languageId, keyboardId, GetCultureInfoName(languageId), GetCultureInfoName(keyboardId));

            String GetCultureInfoName(UInt16 cultureId)
            {
                return CultureInfo.GetCultureInfo(cultureId).DisplayName;
            }
        }

        private static UInt32 SetKeyboardLayout(UInt32 keyboardLayoutId, UInt32 flags)
        {
            return ActivateKeyboardLayout((IntPtr)keyboardLayoutId, flags);
        }

        [DllImport("user32.dll")]
        private static extern IntPtr GetKeyboardLayout(UInt32 idThread);

        [DllImport("user32.dll")]
        private static extern UInt32 GetKeyboardLayoutList(Int32 nBuff, IntPtr[] lpList);

        private const UInt32 KLF_SETFORPROCESS = 0x00000100;

        [DllImport("user32.dll")]
        private static extern UInt32 ActivateKeyboardLayout(IntPtr hkl, UInt32 flags);
    }
}