NativeInput.cs

using System.Runtime.InteropServices;

namespace MidiShortcuts;

/// <summary>
/// Envoltorio de la API SendInput de user32.dll para simular teclas y
/// texto, sin depender de ninguna libreria externa (equivalente al uso
/// que hacia el proyecto en Python de la libreria "keyboard").
/// </summary>
internal static class NativeInput
{
    internal const uint INPUT_KEYBOARD = 1;
    internal const uint KEYEVENTF_EXTENDEDKEY = 0x0001;
    internal const uint KEYEVENTF_KEYUP = 0x0002;
    internal const uint KEYEVENTF_UNICODE = 0x0004;

    [StructLayout(LayoutKind.Sequential)]
    internal struct KEYBDINPUT
    {
        public ushort wVk;
        public ushort wScan;
        public uint dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct MOUSEINPUT
    {
        public int dx;
        public int dy;
        public uint mouseData;
        public uint dwFlags;
        public uint time;
        public IntPtr dwExtraInfo;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct HARDWAREINPUT
    {
        public uint uMsg;
        public ushort wParamL;
        public ushort wParamH;
    }

    [StructLayout(LayoutKind.Explicit)]
    internal struct InputUnion
    {
        [FieldOffset(0)] public MOUSEINPUT mi;
        [FieldOffset(0)] public KEYBDINPUT ki;
        [FieldOffset(0)] public HARDWAREINPUT hi;
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct INPUT
    {
        public uint type;
        public InputUnion U;
    }

    [DllImport("user32.dll", SetLastError = true)]
    internal static extern uint SendInput(uint nInputs, INPUT[] pInputs, int cbSize);
}