AutohotkeyToMahappsHotKeyConverter.cs

using System;
using System.Globalization;
using System.Windows.Data;
using System.Windows.Input;
using MahApps.Metro.Controls;

namespace ChangeThis
{
    public class AutohotkeyToMahappsHotKeyConverter : IValueConverter
    {
        public object Convert(object value, Type targetType = null, object parameter = null, CultureInfo culture = null)
        {
            if (!(value is string shortcut))
            {
                return null;
            }

            bool shift = shortcut.Contains("+");
            bool ctrl = shortcut.Contains("^");
            bool alt = shortcut.Contains("!");
            bool windows = shortcut.Contains("#");

            ModifierKeys modifierKeys = ModifierKeys.None;
            if (shift)
            {
                modifierKeys = modifierKeys | ModifierKeys.Shift;
            }

            if (alt)
            {
                modifierKeys = modifierKeys | ModifierKeys.Alt;
            }

            if (ctrl)
            {
                modifierKeys = modifierKeys | ModifierKeys.Control;
            }

            if (windows)
            {
                modifierKeys = modifierKeys | ModifierKeys.Windows;
            }

            string keyString = shortcut.Trim('+', '!', '^', '#');

            keyString = int.TryParse(keyString, out int _) ? $"D{keyString}" : keyString; // if string is number, add D to beginning to correct enum conversion
            Key key = (Key) Enum.Parse(typeof(Key), keyString, true);

            return new HotKey(key, modifierKeys);
        }

        public object ConvertBack(object value, Type targetType = null, object parameter = null, CultureInfo culture = null)
        {
            if (!(value is HotKey hotkey))
            {
                return null;
            }

            string ahkKey = "";
            if (hotkey.ModifierKeys.Has(ModifierKeys.Control))
            {
                ahkKey += "^";
            }

            if (hotkey.ModifierKeys.Has(ModifierKeys.Shift))
            {
                ahkKey += "+";
            }

            if (hotkey.ModifierKeys.Has(ModifierKeys.Alt))
            {
                ahkKey += "!";
            }

            if (hotkey.ModifierKeys.Has(ModifierKeys.Windows))
            {
                ahkKey += "#";
            }

            /*if key is number, it happens like this D0 D1 D2... and we don`t need the 'D'*/
            if (hotkey.Key >= Key.D0
             && hotkey.Key <= Key.D9)
            {
                ahkKey += hotkey.Key.ToString()[1];
            }
            /*if it is a function key*/
            else if (hotkey.Key >= Key.F1
             && hotkey.Key <= Key.F12)
            {
                ahkKey += hotkey.Key.ToString();
            }

            else if (hotkey.Key >= Key.A && hotkey.Key <= Key.Z)
            {
                ahkKey += hotkey.Key.ToString();
            }

            return ahkKey;
        }
    }
}

EnumerationExtensions.cs

public static class EnumerationExtensions
{
    public static bool Has<T>(this Enum type, T value)
    {
        try
        {
            return ((int) (object) type & (int) (object) value) == (int) (object) value;
        }
        catch
        {
            return false;
        }
    }

    public static bool Is<T>(this Enum type, T value)
    {
        try
        {
            return (int) (object) type == (int) (object) value;
        }
        catch
        {
            return false;
        }
    }


    public static T Add<T>(this Enum type, T value)
    {
        try
        {
            return (T) (object) ((int) (object) type | (int) (object) value);
        }
        catch (Exception ex)
        {
            throw new ArgumentException($"Could not append value from enumerated type '{typeof(T).Name}'.", ex);
        }
    }


    public static T Remove<T>(this Enum type, T value)
    {
        try
        {
            return (T) (object) ((int) (object) type & ~(int) (object) value);
        }
        catch (Exception ex)
        {
            throw new ArgumentException($"Could not remove value from enumerated type '{typeof(T).Name}'.", ex);
        }
    }
}