Simulate keyboard input in C#

Question

I need to know how to simulate keyboard input for keys W, S, A, D.

I've used SendKeys with no avail as well as the InputSimulator library with no fix.

What I'm trying to do is make it to where applications such as games (Battlefield, Natural Selection, ect. Newer FPS games) will register these simulated keys as real keystrokes. I'm trying to make a virtual controller program where external controls will register as keyboard inputs for these games.

Is there a way to manually simulate keyboard input like there is with something like this?

[DllImport("user32.dll", 
           CharSet = CharSet.Auto, 
           CallingConvention = CallingConvention.StdCall)]
public static extern void mouse_event(uint dwFlags, 
                                      uint dx, 
                                      uint dy, 
                                      int cButtons, 
                                      uint dwExtraInfo);

Answer 1

Adding on to the great answer from @gareth, to simulate capital letters during a sentance you can use my solution below..

public static void SendWithShift(ScanCodeShort a){
    HoldLShift();
    Send(a);
    ReleaseLShift();
}
public static void HoldLShift(){
    var Inputs = new InputStruct[1];
    var Input = new InputStruct();
    Input.type = 1; 
    Input.U.ki.wScan = ScanCodeShort.LSHIFT;
    Input.U.ki.dwFlags = KeyEventF.SCANCODE;
    Inputs[0] = Input;
    SendInput(1, Inputs, InputStruct.Size);
}
public static void ReleaseLShift(){
    var Inputs = new InputStruct[1];
    var Input = new InputStruct();
    Input.type = 1; 
    Input.U.ki.wScan = ScanCodeShort.LSHIFT;
    Input.U.ki.dwFlags = KeyEventF.KEYUP | KeyEventF.SCANCODE;
    Inputs[0] = Input;
    SendInput(1, Inputs, InputStruct.Size);
}
public static void Send(ScanCodeShort a){
    var Inputs = new InputStruct[1];
    var Input = new InputStruct();
    Input.type = 1;
    Input.U.ki.wScan = a;
    Input.U.ki.dwFlags = KeyEventF.SCANCODE;
    Inputs[0] = Input;
    SendInput(1, Inputs, InputStruct.Size);
}

To send shift and hold, you simply need to send but to release shift you need to ADD the keyup flag, not just set it.

Answer 2

I was looking for emulation of multimedia button presses and found that you need to use these parameters(in @Gareth code): Input.U.ki.wVk = VirtualKeyShort.VOLUME_MUTE; Input.U.ki.dwFlags = KEYEVENTF.UNICODE;

Answer 3

keybd_event should do the job:

     // Simulate a key press
     keybd_event( VK_NUMLOCK,
                  0x45,
                  KEYEVENTF_EXTENDEDKEY | 0,
                  0 );

     // Simulate a key release
     keybd_event( VK_NUMLOCK,
                  0x45,
                  KEYEVENTF_EXTENDEDKEY | KEYEVENTF_KEYUP,
                  0);

More info: http://msdn.microsoft.com/en-us/library/windows/desktop/ms646304(v=vs.85).aspx

Answer 4

Windows Input Simulator makes this super easy.

The Windows Input Simulator provides a simple .NET (C#) interface to simulate Keyboard or Mouse input using the Win32 SendInput method. All of the Interop is done for you and there's a simple programming model for sending multiple keystrokes. Nuget package -> Install-Package InputSimulator

https://inputsimulator.codeplex.com/

Answer 5

Have you tried using SendInput which supersedes keybd_event?

To call SendInput from C#, you're going to need to create a whole bunch of structs. Fortunately, most of this information can be gleaned from pinvoke.net.

Looking at the pinvoke documentation for SendInput and the INPUT struct, I came up with the following. The method I've written at the top called SendInputWithAPI is calling SendInput to simulate the sending of "wsad". The rest of the code is just the structure declarations you need to make it work.

    void SendInputWithAPI()
    {
        INPUT[] Inputs = new INPUT[4];
        INPUT Input = new INPUT();

        Input.type = 1; // 1 = Keyboard Input
        Input.U.ki.wScan = ScanCodeShort.KEY_W;
        Input.U.ki.dwFlags = KEYEVENTF.SCANCODE;   
        Inputs[0] = Input;

        Input.type = 1; // 1 = Keyboard Input
        Input.U.ki.wScan = ScanCodeShort.KEY_S;
        Input.U.ki.dwFlags = KEYEVENTF.SCANCODE;
        Inputs[1] = Input;

        Input.type = 1; // 1 = Keyboard Input
        Input.U.ki.wScan = ScanCodeShort.KEY_A;
        Input.U.ki.dwFlags = KEYEVENTF.SCANCODE;
        Inputs[2] = Input;

        Input.type = 1; // 1 = Keyboard Input
        Input.U.ki.wScan = ScanCodeShort.KEY_D;
        Input.U.ki.dwFlags = KEYEVENTF.SCANCODE;
        Inputs[3] = Input;


        SendInput(4, Inputs, INPUT.Size);
    }

    /// <summary>
    /// Declaration of external SendInput method
    /// </summary>
    [DllImport("user32.dll")]
    internal static extern uint SendInput(
        uint nInputs,
        [MarshalAs(UnmanagedType.LPArray), In] INPUT[] pInputs,
        int cbSize);


    // Declare the INPUT struct
    [StructLayout(LayoutKind.Sequential)]
    public struct INPUT
    {
        internal uint type;
        internal InputUnion U;
        internal static int Size
        {
            get { return Marshal.SizeOf(typeof(INPUT)); }
        }
    }

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

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

    [Flags]
    internal enum MouseEventDataXButtons : uint
    {
        Nothing = 0x00000000,
        XBUTTON1 = 0x00000001,
        XBUTTON2 = 0x00000002
    }

    [Flags]
    internal enum MOUSEEVENTF : uint
    {
        ABSOLUTE = 0x8000,
        HWHEEL = 0x01000,
        MOVE = 0x0001,
        MOVE_NOCOALESCE = 0x2000,
        LEFTDOWN = 0x0002,
        LEFTUP = 0x0004,
        RIGHTDOWN = 0x0008,
        RIGHTUP = 0x0010,
        MIDDLEDOWN = 0x0020,
        MIDDLEUP = 0x0040,
        VIRTUALDESK = 0x4000,
        WHEEL = 0x0800,
        XDOWN = 0x0080,
        XUP = 0x0100
    }

    [StructLayout(LayoutKind.Sequential)]
    internal struct KEYBDINPUT
    {
        internal VirtualKeyShort wVk;
        internal ScanCodeShort wScan;
        internal KEYEVENTF dwFlags;
        internal int time;
        internal UIntPtr dwExtraInfo;
    }

    [Flags]
    internal enum KEYEVENTF : uint
    {
        EXTENDEDKEY = 0x0001,
        KEYUP = 0x0002,
        SCANCODE = 0x0008,
        UNICODE = 0x0004
    }

    internal enum VirtualKeyShort : short
    {
        ///<summary>
        ///Left mouse button
        ///</summary>
        LBUTTON = 0x01,
        ///<summary>
        ///Right mouse button
        ///</summary>
        RBUTTON = 0x02,
        ///<summary>
        ///Control-break processing
        ///</summary>
        CANCEL = 0x03,
        ///<summary>
        ///Middle mouse button (three-button mouse)
        ///</summary>
        MBUTTON = 0x04,
        ///<summary>
        ///Windows 2000/XP: X1 mouse button
        ///</summary>
        XBUTTON1 = 0x05,
        ///<summary>
        ///Windows 2000/XP: X2 mouse button
        ///</summary>
        XBUTTON2 = 0x06,
        ///<summary>
        ///BACKSPACE key
        ///</summary>
        BACK = 0x08,
        ///<summary>
        ///TAB key
        ///</summary>
        TAB = 0x09,
        ///<summary>
        ///CLEAR key
        ///</summary>
        CLEAR = 0x0C,
        ///<summary>
        ///ENTER key
        ///</summary>
        RETURN = 0x0D,
        ///<summary>
        ///SHIFT key
        ///</summary>
        SHIFT = 0x10,
        ///<summary>
        ///CTRL key
        ///</summary>
        CONTROL = 0x11,
        ///<summary>
        ///ALT key
        ///</summary>
        MENU = 0x12,
        ///<summary>
        ///PAUSE key
        ///</summary>
        PAUSE = 0x13,
        ///<summary>
        ///CAPS LOCK key
        ///</summary>
        CAPITAL = 0x14,
        ///<summary>
        ///Input Method Editor (IME) Kana mode
        ///</summary>
        KANA = 0x15,
        ///<summary>
        ///IME Hangul mode
        ///</summary>
        HANGUL = 0x15,
        ///<summary>
        ///IME Junja mode
        ///</summary>
        JUNJA = 0x17,
        ///<summary>
        ///IME final mode
        ///</summary>
        FINAL = 0x18,
        ///<summary>
        ///IME Hanja mode
        ///</summary>
        HANJA = 0x19,
        ///<summary>
        ///IME Kanji mode
        ///</summary>
        KANJI = 0x19,
        ///<summary>
        ///ESC key
        ///</summary>
        ESCAPE = 0x1B,
        ///<summary>
        ///IME convert
        ///</summary>
        CONVERT = 0x1C,
        ///<summary>
        ///IME nonconvert
        ///</summary>
        NONCONVERT = 0x1D,
        ///<summary>
        ///IME accept
        ///</summary>
        ACCEPT = 0x1E,
        ///<summary>
        ///IME mode change request
        ///</summary>
        MODECHANGE = 0x1F,
        ///<summary>
        ///SPACEBAR
        ///</summary>
        SPACE = 0x20,
        ///<summary>
        ///PAGE UP key
        ///</summary>
        PRIOR = 0x21,
        ///<summary>
        ///PAGE DOWN key
        ///</summary>
        NEXT = 0x22,
        ///<summary>
        ///END key
        ///</summary>
        END = 0x23,
        ///<summary>
        ///HOME key
        ///</summary>
        HOME = 0x24,
        ///<summary>
        ///LEFT ARROW key
        ///</summary>
        LEFT = 0x25,
        ///<summary>
        ///UP ARROW key
        ///</summary>
        UP = 0x26,
        ///<summary>
        ///RIGHT ARROW key
        ///</summary>
        RIGHT = 0x27,
        ///<summary>
        ///DOWN ARROW key
        ///</summary>
        DOWN = 0x28,
        ///<summary>
        ///SELECT key
        ///</summary>
        SELECT = 0x29,
        ///<summary>
        ///PRINT key
        ///</summary>
        PRINT = 0x2A,
        ///<summary>
        ///EXECUTE key
        ///</summary>
        EXECUTE = 0x2B,
        ///<summary>
        ///PRINT SCREEN key
        ///</summary>
        SNAPSHOT = 0x2C,
        ///<summary>
        ///INS key
        ///</summary>
        INSERT = 0x2D,
        ///<summary>
        ///DEL key
        ///</summary>
        DELETE = 0x2E,
        ///<summary>
        ///HELP key
        ///</summary>
        HELP = 0x2F,
        ///<summary>
        ///0 key
        ///</summary>
        KEY_0 = 0x30,
        ///<summary>
        ///1 key
        ///</summary>
        KEY_1 = 0x31,
        ///<summary>
        ///2 key
        ///</summary>
        KEY_2 = 0x32,
        ///<summary>
        ///3 key
        ///</summary>
        KEY_3 = 0x33,
        ///<summary>
        ///4 key
        ///</summary>
        KEY_4 = 0x34,
        ///<summary>
        ///5 key
        ///</summary>
        KEY_5 = 0x35,
        ///<summary>
        ///6 key
        ///</summary>
        KEY_6 = 0x36,
        ///<summary>
        ///7 key
        ///</summary>
        KEY_7 = 0x37,
        ///<summary>
        ///8 key
        ///</summary>
        KEY_8 = 0x38,
        ///<summary>
        ///9 key
        ///</summary>
        KEY_9 = 0x39,
        ///<summary>
        ///A key
        ///</summary>
        KEY_A = 0x41,
        ///<summary>
        ///B key
        ///</summary>
        KEY_B = 0x42,
        ///<summary>
        ///C key
        ///</summary>
        KEY_C = 0x43,
        ///<summary>
        ///D key
        ///</summary>
        KEY_D = 0x44,
        ///<summary>
        ///E key
        ///</summary>
        KEY_E = 0x45,
        ///<summary>
        ///F key
        ///</summary>
        KEY_F = 0x46,
        ///<summary>
        ///G key
        ///</summary>
        KEY_G = 0x47,
        ///<summary>
        ///H key
        ///</summary>
        KEY_H = 0x48,
        ///<summary>
        ///I key
        ///</summary>
        KEY_I = 0x49,
        ///<summary>
        ///J key
        ///</summary>
        KEY_J = 0x4A,
        ///<summary>
        ///K key
        ///</summary>
        KEY_K = 0x4B,
        ///<summary>
        ///L key
        ///</summary>
        KEY_L = 0x4C,
        ///<summary>
        ///M key
        ///</summary>
        KEY_M = 0x4D,
        ///<summary>
        ///N key
        ///</summary>
        KEY_N = 0x4E,
        ///<summary>
        ///O key
        ///</summary>
        KEY_O = 0x4F,
        ///<summary>
        ///P key
        ///</summary>
        KEY_P = 0x50,
        ///<summary>
        ///Q key
        ///</summary>
        KEY_Q = 0x51,
        ///<summary>
        ///R key
        ///</summary>
        KEY_R = 0x52,
        ///<summary>
        ///S key
        ///</summary>
        KEY_S = 0x53,
        ///<summary>
        ///T key
        ///</summary>
        KEY_T = 0x54,
        ///<summary>
        ///U key
        ///</summary>
        KEY_U = 0x55,
        ///<summary>
        ///V key
        ///</summary>
        KEY_V = 0x56,
        ///<summary>
        ///W key
        ///</summary>
        KEY_W = 0x57,
        ///<summary>
        ///X key
        ///</summary>
        KEY_X = 0x58,
        ///<summary>
        ///Y key
        ///</summary>
        KEY_Y = 0x59,
        ///<summary>
        ///Z key
        ///</summary>
        KEY_Z = 0x5A,
        ///<summary>
        ///Left Windows key (Microsoft Natural keyboard) 
        ///</summary>
        LWIN = 0x5B,
        ///<summary>
        ///Right Windows key (Natural keyboard)
        ///</summary>
        RWIN = 0x5C,
        ///<summary>
        ///Applications key (Natural keyboard)
        ///</summary>
        APPS = 0x5D,
        ///<summary>
        ///Computer Sleep key
        ///</summary>
        SLEEP = 0x5F,
        ///<summary>
        ///Numeric keypad 0 key
        ///</summary>
        NUMPAD0 = 0x60,
        ///<summary>
        ///Numeric keypad 1 key
        ///</summary>
        NUMPAD1 = 0x61,
        ///<summary>
        ///Numeric keypad 2 key
        ///</summary>
        NUMPAD2 = 0x62,
        ///<summary>
        ///Numeric keypad 3 key
        ///</summary>
        NUMPAD3 = 0x63,
        ///<summary>
        ///Numeric keypad 4 key
        ///</summary>
        NUMPAD4 = 0x64,
        ///<summary>
        ///Numeric keypad 5 key
        ///</summary>
        NUMPAD5 = 0x65,
        ///<summary>
        ///Numeric keypad 6 key
        ///</summary>
        NUMPAD6 = 0x66,
        ///<summary>
        ///Numeric keypad 7 key
        ///</summary>
        NUMPAD7 = 0x67,
        ///<summary>
        ///Numeric keypad 8 key
        ///</summary>
        NUMPAD8 = 0x68,
        ///<summary>
        ///Numeric keypad 9 key
        ///</summary>
        NUMPAD9 = 0x69,
        ///<summary>
        ///Multiply key
        ///</summary>
        MULTIPLY = 0x6A,
        ///<summary>
        ///Add key
        ///</summary>
        ADD = 0x6B,
        ///<summary>
        ///Separator key
        ///</summary>
        SEPARATOR = 0x6C,
        ///<summary>
        ///Subtract key
        ///</summary>
        SUBTRACT = 0x6D,
        ///<summary>
        ///Decimal key
        ///</summary>
        DECIMAL = 0x6E,
        ///<summary>
        ///Divide key
        ///</summary>
        DIVIDE = 0x6F,
        ///<summary>
        ///F1 key
        ///</summary>
        F1 = 0x70,
        ///<summary>
        ///F2 key
        ///</summary>
        F2 = 0x71,
        ///<summary>
        ///F3 key
        ///</summary>
        F3 = 0x72,
        ///<summary>
        ///F4 key
        ///</summary>
        F4 = 0x73,
        ///<summary>
        ///F5 key
        ///</summary>
        F5 = 0x74,
        ///<summary>
        ///F6 key
        ///</summary>
        F6 = 0x75,
        ///<summary>
        ///F7 key
        ///</summary>
        F7 = 0x76,
        ///<summary>
        ///F8 key
        ///</summary>
        F8 = 0x77,
        ///<summary>
        ///F9 key
        ///</summary>
        F9 = 0x78,
        ///<summary>
        ///F10 key
        ///</summary>
        F10 = 0x79,
        ///<summary>
        ///F11 key
        ///</summary>
        F11 = 0x7A,
        ///<summary>
        ///F12 key
        ///</summary>
        F12 = 0x7B,
        ///<summary>
        ///F13 key
        ///</summary>
        F13 = 0x7C,
        ///<summary>
        ///F14 key
        ///</summary>
        F14 = 0x7D,
        ///<summary>
        ///F15 key
        ///</summary>
        F15 = 0x7E,
        ///<summary>
        ///F16 key
        ///</summary>
        F16 = 0x7F,
        ///<summary>
        ///F17 key  
        ///</summary>
        F17 = 0x80,
        ///<summary>
        ///F18 key  
        ///</summary>
        F18 = 0x81,
        ///<summary>
        ///F19 key  
        ///</summary>
        F19 = 0x82,
        ///<summary>
        ///F20 key  
        ///</summary>
        F20 = 0x83,
        ///<summary>
        ///F21 key  
        ///</summary>
        F21 = 0x84,
        ///<summary>
        ///F22 key, (PPC only) Key used to lock device.
        ///</summary>
        F22 = 0x85,
        ///<summary>
        ///F23 key  
        ///</summary>
        F23 = 0x86,
        ///<summary>
        ///F24 key  
        ///</summary>
        F24 = 0x87,
        ///<summary>
        ///NUM LOCK key
        ///</summary>
        NUMLOCK = 0x90,
        ///<summary>
        ///SCROLL LOCK key
        ///</summary>
        SCROLL = 0x91,
        ///<summary>
        ///Left SHIFT key
        ///</summary>
        LSHIFT = 0xA0,
        ///<summary>
        ///Right SHIFT key
        ///</summary>
        RSHIFT = 0xA1,
        ///<summary>
        ///Left CONTROL key
        ///</summary>
        LCONTROL = 0xA2,
        ///<summary>
        ///Right CONTROL key
        ///</summary>
        RCONTROL = 0xA3,
        ///<summary>
        ///Left MENU key
        ///</summary>
        LMENU = 0xA4,
        ///<summary>
        ///Right MENU key
        ///</summary>
        RMENU = 0xA5,
        ///<summary>
        ///Windows 2000/XP: Browser Back key
        ///</summary>
        BROWSER_BACK = 0xA6,
        ///<summary>
        ///Windows 2000/XP: Browser Forward key
        ///</summary>
        BROWSER_FORWARD = 0xA7,
        ///<summary>
        ///Windows 2000/XP: Browser Refresh key
        ///</summary>
        BROWSER_REFRESH = 0xA8,
        ///<summary>
        ///Windows 2000/XP: Browser Stop key
        ///</summary>
        BROWSER_STOP = 0xA9,
        ///<summary>
        ///Windows 2000/XP: Browser Search key 
        ///</summary>
        BROWSER_SEARCH = 0xAA,
        ///<summary>
        ///Windows 2000/XP: Browser Favorites key
        ///</summary>
        BROWSER_FAVORITES = 0xAB,
        ///<summary>
        ///Windows 2000/XP: Browser Start and Home key
        ///</summary>
        BROWSER_HOME = 0xAC,
        ///<summary>
        ///Windows 2000/XP: Volume Mute key
        ///</summary>
        VOLUME_MUTE = 0xAD,
        ///<summary>
        ///Windows 2000/XP: Volume Down key
        ///</summary>
        VOLUME_DOWN = 0xAE,
        ///<summary>
        ///Windows 2000/XP: Volume Up key
        ///</summary>
        VOLUME_UP = 0xAF,
        ///<summary>
        ///Windows 2000/XP: Next Track key
        ///</summary>
        MEDIA_NEXT_TRACK = 0xB0,
        ///<summary>
        ///Windows 2000/XP: Previous Track key
        ///</summary>
        MEDIA_PREV_TRACK = 0xB1,
        ///<summary>
        ///Windows 2000/XP: Stop Media key
        ///</summary>
        MEDIA_STOP = 0xB2,
        ///<summary>
        ///Windows 2000/XP: Play/Pause Media key
        ///</summary>
        MEDIA_PLAY_PAUSE = 0xB3,
        ///<summary>
        ///Windows 2000/XP: Start Mail key
        ///</summary>
        LAUNCH_MAIL = 0xB4,
        ///<summary>
        ///Windows 2000/XP: Select Media key
        ///</summary>
        LAUNCH_MEDIA_SELECT = 0xB5,
        ///<summary>
        ///Windows 2000/XP: Start Application 1 key
        ///</summary>
        LAUNCH_APP1 = 0xB6,
        ///<summary>
        ///Windows 2000/XP: Start Application 2 key
        ///</summary>
        LAUNCH_APP2 = 0xB7,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_1 = 0xBA,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '+' key
        ///</summary>
        OEM_PLUS = 0xBB,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the ',' key
        ///</summary>
        OEM_COMMA = 0xBC,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '-' key
        ///</summary>
        OEM_MINUS = 0xBD,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '.' key
        ///</summary>
        OEM_PERIOD = 0xBE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_2 = 0xBF,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_3 = 0xC0,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_4 = 0xDB,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_5 = 0xDC,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_6 = 0xDD,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_7 = 0xDE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_8 = 0xDF,
        ///<summary>
        ///Windows 2000/XP: Either the angle bracket key or the backslash key on the RT 102-key keyboard
        ///</summary>
        OEM_102 = 0xE2,
        ///<summary>
        ///Windows 95/98/Me, Windows NT 4.0, Windows 2000/XP: IME PROCESS key
        ///</summary>
        PROCESSKEY = 0xE5,
        ///<summary>
        ///Windows 2000/XP: Used to pass Unicode characters as if they were keystrokes.
        ///The VK_PACKET key is the low word of a 32-bit Virtual Key value used for non-keyboard input methods. For more information,
        ///see Remark in KEYBDINPUT, SendInput, WM_KEYDOWN, and WM_KEYUP
        ///</summary>
        PACKET = 0xE7,
        ///<summary>
        ///Attn key
        ///</summary>
        ATTN = 0xF6,
        ///<summary>
        ///CrSel key
        ///</summary>
        CRSEL = 0xF7,
        ///<summary>
        ///ExSel key
        ///</summary>
        EXSEL = 0xF8,
        ///<summary>
        ///Erase EOF key
        ///</summary>
        EREOF = 0xF9,
        ///<summary>
        ///Play key
        ///</summary>
        PLAY = 0xFA,
        ///<summary>
        ///Zoom key
        ///</summary>
        ZOOM = 0xFB,
        ///<summary>
        ///Reserved 
        ///</summary>
        NONAME = 0xFC,
        ///<summary>
        ///PA1 key
        ///</summary>
        PA1 = 0xFD,
        ///<summary>
        ///Clear key
        ///</summary>
        OEM_CLEAR = 0xFE
    }

    internal enum ScanCodeShort : short
    {
        LBUTTON = 0,
        RBUTTON = 0,
        CANCEL = 70,
        MBUTTON = 0,
        XBUTTON1 = 0,
        XBUTTON2 = 0,
        BACK = 14,
        TAB = 15,
        CLEAR = 76,
        RETURN = 28,
        SHIFT = 42,
        CONTROL = 29,
        MENU = 56,
        PAUSE = 0,
        CAPITAL = 58,
        KANA = 0,
        HANGUL = 0,
        JUNJA = 0,
        FINAL = 0,
        HANJA = 0,
        KANJI = 0,
        ESCAPE = 1,
        CONVERT = 0,
        NONCONVERT = 0,
        ACCEPT = 0,
        MODECHANGE = 0,
        SPACE = 57,
        PRIOR = 73,
        NEXT = 81,
        END = 79,
        HOME = 71,
        LEFT = 75,
        UP = 72,
        RIGHT = 77,
        DOWN = 80,
        SELECT = 0,
        PRINT = 0,
        EXECUTE = 0,
        SNAPSHOT = 84,
        INSERT = 82,
        DELETE = 83,
        HELP = 99,
        KEY_0 = 11,
        KEY_1 = 2,
        KEY_2 = 3,
        KEY_3 = 4,
        KEY_4 = 5,
        KEY_5 = 6,
        KEY_6 = 7,
        KEY_7 = 8,
        KEY_8 = 9,
        KEY_9 = 10,
        KEY_A = 30,
        KEY_B = 48,
        KEY_C = 46,
        KEY_D = 32,
        KEY_E = 18,
        KEY_F = 33,
        KEY_G = 34,
        KEY_H = 35,
        KEY_I = 23,
        KEY_J = 36,
        KEY_K = 37,
        KEY_L = 38,
        KEY_M = 50,
        KEY_N = 49,
        KEY_O = 24,
        KEY_P = 25,
        KEY_Q = 16,
        KEY_R = 19,
        KEY_S = 31,
        KEY_T = 20,
        KEY_U = 22,
        KEY_V = 47,
        KEY_W = 17,
        KEY_X = 45,
        KEY_Y = 21,
        KEY_Z = 44,
        LWIN = 91,
        RWIN = 92,
        APPS = 93,
        SLEEP = 95,
        NUMPAD0 = 82,
        NUMPAD1 = 79,
        NUMPAD2 = 80,
        NUMPAD3 = 81,
        NUMPAD4 = 75,
        NUMPAD5 = 76,
        NUMPAD6 = 77,
        NUMPAD7 = 71,
        NUMPAD8 = 72,
        NUMPAD9 = 73,
        MULTIPLY = 55,
        ADD = 78,
        SEPARATOR = 0,
        SUBTRACT = 74,
        DECIMAL = 83,
        DIVIDE = 53,
        F1 = 59,
        F2 = 60,
        F3 = 61,
        F4 = 62,
        F5 = 63,
        F6 = 64,
        F7 = 65,
        F8 = 66,
        F9 = 67,
        F10 = 68,
        F11 = 87,
        F12 = 88,
        F13 = 100,
        F14 = 101,
        F15 = 102,
        F16 = 103,
        F17 = 104,
        F18 = 105,
        F19 = 106,
        F20 = 107,
        F21 = 108,
        F22 = 109,
        F23 = 110,
        F24 = 118,
        NUMLOCK = 69,
        SCROLL = 70,
        LSHIFT = 42,
        RSHIFT = 54,
        LCONTROL = 29,
        RCONTROL = 29,
        LMENU = 56,
        RMENU = 56,
        BROWSER_BACK = 106,
        BROWSER_FORWARD = 105,
        BROWSER_REFRESH = 103,
        BROWSER_STOP = 104,
        BROWSER_SEARCH = 101,
        BROWSER_FAVORITES = 102,
        BROWSER_HOME = 50,
        VOLUME_MUTE = 32,
        VOLUME_DOWN = 46,
        VOLUME_UP = 48,
        MEDIA_NEXT_TRACK = 25,
        MEDIA_PREV_TRACK = 16,
        MEDIA_STOP = 36,
        MEDIA_PLAY_PAUSE = 34,
        LAUNCH_MAIL = 108,
        LAUNCH_MEDIA_SELECT = 109,
        LAUNCH_APP1 = 107,
        LAUNCH_APP2 = 33,
        OEM_1 = 39,
        OEM_PLUS = 13,
        OEM_COMMA = 51,
        OEM_MINUS = 12,
        OEM_PERIOD = 52,
        OEM_2 = 53,
        OEM_3 = 41,
        OEM_4 = 26,
        OEM_5 = 43,
        OEM_6 = 27,
        OEM_7 = 40,
        OEM_8 = 0,
        OEM_102 = 86,
        PROCESSKEY = 0,
        PACKET = 0,
        ATTN = 0,
        CRSEL = 0,
        EXSEL = 0,
        EREOF = 93,
        PLAY = 0,
        ZOOM = 98,
        NONAME = 0,
        PA1 = 0,
        OEM_CLEAR = 0,
    }

    /// <summary>
    /// Define HARDWAREINPUT struct
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    internal struct HARDWAREINPUT
    {
        internal int uMsg;
        internal short wParamL;
        internal short wParamH;
    }

Answer 6

I like Gareth's approach at it. However, in his method, you need to hard code your key strokes into the SendInputWithAPI() method. I made a few changes to the code; you now can call Send() and pass ScanCodeShort parameter to it. This allows you to pass any keystroke to it, any time, any place.

 public class Keyboard
{
    public void Send(ScanCodeShort a)
    {
        INPUT[] Inputs = new INPUT[1];
        INPUT Input = new INPUT();
        Input.type = 1; // 1 = Keyboard Input
        Input.U.ki.wScan = a;
        Input.U.ki.dwFlags = KEYEVENTF.SCANCODE;
        Inputs[0] = Input;
        SendInput(1, Inputs, INPUT.Size);
    }

    /// <summary>
    /// Declaration of external SendInput method
    /// </summary>
    [DllImport("user32.dll")]
    internal static extern uint SendInput(
        uint nInputs,
        [MarshalAs(UnmanagedType.LPArray), In] INPUT[] pInputs,
        int cbSize);


    // Declare the INPUT struct
    [StructLayout(LayoutKind.Sequential)]
    public struct INPUT
    {
        public uint type;
        public InputUnion U;
        public static int Size
        {
            get { return Marshal.SizeOf(typeof(INPUT)); }
        }
    }

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

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

    [Flags]
    public enum MouseEventDataXButtons : uint
    {
        Nothing = 0x00000000,
        XBUTTON1 = 0x00000001,
        XBUTTON2 = 0x00000002
    }

    [Flags]
    public enum MOUSEEVENTF : uint
    {
        ABSOLUTE = 0x8000,
        HWHEEL = 0x01000,
        MOVE = 0x0001,
        MOVE_NOCOALESCE = 0x2000,
        LEFTDOWN = 0x0002,
        LEFTUP = 0x0004,
        RIGHTDOWN = 0x0008,
        RIGHTUP = 0x0010,
        MIDDLEDOWN = 0x0020,
        MIDDLEUP = 0x0040,
        VIRTUALDESK = 0x4000,
        WHEEL = 0x0800,
        XDOWN = 0x0080,
        XUP = 0x0100
    }

    [StructLayout(LayoutKind.Sequential)]
    public struct KEYBDINPUT
    {
        internal VirtualKeyShort wVk;
        internal ScanCodeShort wScan;
        internal KEYEVENTF dwFlags;
        internal int time;
        internal UIntPtr dwExtraInfo;
    }

    [Flags]
    public enum KEYEVENTF : uint
    {
        EXTENDEDKEY = 0x0001,
        KEYUP = 0x0002,
        SCANCODE = 0x0008,
        UNICODE = 0x0004
    }

    public enum VirtualKeyShort : short
    {
        ///<summary>
        ///Left mouse button
        ///</summary>
        LBUTTON = 0x01,
        ///<summary>
        ///Right mouse button
        ///</summary>
        RBUTTON = 0x02,
        ///<summary>
        ///Control-break processing
        ///</summary>
        CANCEL = 0x03,
        ///<summary>
        ///Middle mouse button (three-button mouse)
        ///</summary>
        MBUTTON = 0x04,
        ///<summary>
        ///Windows 2000/XP: X1 mouse button
        ///</summary>
        XBUTTON1 = 0x05,
        ///<summary>
        ///Windows 2000/XP: X2 mouse button
        ///</summary>
        XBUTTON2 = 0x06,
        ///<summary>
        ///BACKSPACE key
        ///</summary>
        BACK = 0x08,
        ///<summary>
        ///TAB key
        ///</summary>
        TAB = 0x09,
        ///<summary>
        ///CLEAR key
        ///</summary>
        CLEAR = 0x0C,
        ///<summary>
        ///ENTER key
        ///</summary>
        RETURN = 0x0D,
        ///<summary>
        ///SHIFT key
        ///</summary>
        SHIFT = 0x10,
        ///<summary>
        ///CTRL key
        ///</summary>
        CONTROL = 0x11,
        ///<summary>
        ///ALT key
        ///</summary>
        MENU = 0x12,
        ///<summary>
        ///PAUSE key
        ///</summary>
        PAUSE = 0x13,
        ///<summary>
        ///CAPS LOCK key
        ///</summary>
        CAPITAL = 0x14,
        ///<summary>
        ///Input Method Editor (IME) Kana mode
        ///</summary>
        KANA = 0x15,
        ///<summary>
        ///IME Hangul mode
        ///</summary>
        HANGUL = 0x15,
        ///<summary>
        ///IME Junja mode
        ///</summary>
        JUNJA = 0x17,
        ///<summary>
        ///IME final mode
        ///</summary>
        FINAL = 0x18,
        ///<summary>
        ///IME Hanja mode
        ///</summary>
        HANJA = 0x19,
        ///<summary>
        ///IME Kanji mode
        ///</summary>
        KANJI = 0x19,
        ///<summary>
        ///ESC key
        ///</summary>
        ESCAPE = 0x1B,
        ///<summary>
        ///IME convert
        ///</summary>
        CONVERT = 0x1C,
        ///<summary>
        ///IME nonconvert
        ///</summary>
        NONCONVERT = 0x1D,
        ///<summary>
        ///IME accept
        ///</summary>
        ACCEPT = 0x1E,
        ///<summary>
        ///IME mode change request
        ///</summary>
        MODECHANGE = 0x1F,
        ///<summary>
        ///SPACEBAR
        ///</summary>
        SPACE = 0x20,
        ///<summary>
        ///PAGE UP key
        ///</summary>
        PRIOR = 0x21,
        ///<summary>
        ///PAGE DOWN key
        ///</summary>
        NEXT = 0x22,
        ///<summary>
        ///END key
        ///</summary>
        END = 0x23,
        ///<summary>
        ///HOME key
        ///</summary>
        HOME = 0x24,
        ///<summary>
        ///LEFT ARROW key
        ///</summary>
        LEFT = 0x25,
        ///<summary>
        ///UP ARROW key
        ///</summary>
        UP = 0x26,
        ///<summary>
        ///RIGHT ARROW key
        ///</summary>
        RIGHT = 0x27,
        ///<summary>
        ///DOWN ARROW key
        ///</summary>
        DOWN = 0x28,
        ///<summary>
        ///SELECT key
        ///</summary>
        SELECT = 0x29,
        ///<summary>
        ///PRINT key
        ///</summary>
        PRINT = 0x2A,
        ///<summary>
        ///EXECUTE key
        ///</summary>
        EXECUTE = 0x2B,
        ///<summary>
        ///PRINT SCREEN key
        ///</summary>
        SNAPSHOT = 0x2C,
        ///<summary>
        ///INS key
        ///</summary>
        INSERT = 0x2D,
        ///<summary>
        ///DEL key
        ///</summary>
        DELETE = 0x2E,
        ///<summary>
        ///HELP key
        ///</summary>
        HELP = 0x2F,
        ///<summary>
        ///0 key
        ///</summary>
        KEY_0 = 0x30,
        ///<summary>
        ///1 key
        ///</summary>
        KEY_1 = 0x31,
        ///<summary>
        ///2 key
        ///</summary>
        KEY_2 = 0x32,
        ///<summary>
        ///3 key
        ///</summary>
        KEY_3 = 0x33,
        ///<summary>
        ///4 key
        ///</summary>
        KEY_4 = 0x34,
        ///<summary>
        ///5 key
        ///</summary>
        KEY_5 = 0x35,
        ///<summary>
        ///6 key
        ///</summary>
        KEY_6 = 0x36,
        ///<summary>
        ///7 key
        ///</summary>
        KEY_7 = 0x37,
        ///<summary>
        ///8 key
        ///</summary>
        KEY_8 = 0x38,
        ///<summary>
        ///9 key
        ///</summary>
        KEY_9 = 0x39,
        ///<summary>
        ///A key
        ///</summary>
        KEY_A = 0x41,
        ///<summary>
        ///B key
        ///</summary>
        KEY_B = 0x42,
        ///<summary>
        ///C key
        ///</summary>
        KEY_C = 0x43,
        ///<summary>
        ///D key
        ///</summary>
        KEY_D = 0x44,
        ///<summary>
        ///E key
        ///</summary>
        KEY_E = 0x45,
        ///<summary>
        ///F key
        ///</summary>
        KEY_F = 0x46,
        ///<summary>
        ///G key
        ///</summary>
        KEY_G = 0x47,
        ///<summary>
        ///H key
        ///</summary>
        KEY_H = 0x48,
        ///<summary>
        ///I key
        ///</summary>
        KEY_I = 0x49,
        ///<summary>
        ///J key
        ///</summary>
        KEY_J = 0x4A,
        ///<summary>
        ///K key
        ///</summary>
        KEY_K = 0x4B,
        ///<summary>
        ///L key
        ///</summary>
        KEY_L = 0x4C,
        ///<summary>
        ///M key
        ///</summary>
        KEY_M = 0x4D,
        ///<summary>
        ///N key
        ///</summary>
        KEY_N = 0x4E,
        ///<summary>
        ///O key
        ///</summary>
        KEY_O = 0x4F,
        ///<summary>
        ///P key
        ///</summary>
        KEY_P = 0x50,
        ///<summary>
        ///Q key
        ///</summary>
        KEY_Q = 0x51,
        ///<summary>
        ///R key
        ///</summary>
        KEY_R = 0x52,
        ///<summary>
        ///S key
        ///</summary>
        KEY_S = 0x53,
        ///<summary>
        ///T key
        ///</summary>
        KEY_T = 0x54,
        ///<summary>
        ///U key
        ///</summary>
        KEY_U = 0x55,
        ///<summary>
        ///V key
        ///</summary>
        KEY_V = 0x56,
        ///<summary>
        ///W key
        ///</summary>
        KEY_W = 0x57,
        ///<summary>
        ///X key
        ///</summary>
        KEY_X = 0x58,
        ///<summary>
        ///Y key
        ///</summary>
        KEY_Y = 0x59,
        ///<summary>
        ///Z key
        ///</summary>
        KEY_Z = 0x5A,
        ///<summary>
        ///Left Windows key (Microsoft Natural keyboard) 
        ///</summary>
        LWIN = 0x5B,
        ///<summary>
        ///Right Windows key (Natural keyboard)
        ///</summary>
        RWIN = 0x5C,
        ///<summary>
        ///Applications key (Natural keyboard)
        ///</summary>
        APPS = 0x5D,
        ///<summary>
        ///Computer Sleep key
        ///</summary>
        SLEEP = 0x5F,
        ///<summary>
        ///Numeric keypad 0 key
        ///</summary>
        NUMPAD0 = 0x60,
        ///<summary>
        ///Numeric keypad 1 key
        ///</summary>
        NUMPAD1 = 0x61,
        ///<summary>
        ///Numeric keypad 2 key
        ///</summary>
        NUMPAD2 = 0x62,
        ///<summary>
        ///Numeric keypad 3 key
        ///</summary>
        NUMPAD3 = 0x63,
        ///<summary>
        ///Numeric keypad 4 key
        ///</summary>
        NUMPAD4 = 0x64,
        ///<summary>
        ///Numeric keypad 5 key
        ///</summary>
        NUMPAD5 = 0x65,
        ///<summary>
        ///Numeric keypad 6 key
        ///</summary>
        NUMPAD6 = 0x66,
        ///<summary>
        ///Numeric keypad 7 key
        ///</summary>
        NUMPAD7 = 0x67,
        ///<summary>
        ///Numeric keypad 8 key
        ///</summary>
        NUMPAD8 = 0x68,
        ///<summary>
        ///Numeric keypad 9 key
        ///</summary>
        NUMPAD9 = 0x69,
        ///<summary>
        ///Multiply key
        ///</summary>
        MULTIPLY = 0x6A,
        ///<summary>
        ///Add key
        ///</summary>
        ADD = 0x6B,
        ///<summary>
        ///Separator key
        ///</summary>
        SEPARATOR = 0x6C,
        ///<summary>
        ///Subtract key
        ///</summary>
        SUBTRACT = 0x6D,
        ///<summary>
        ///Decimal key
        ///</summary>
        DECIMAL = 0x6E,
        ///<summary>
        ///Divide key
        ///</summary>
        DIVIDE = 0x6F,
        ///<summary>
        ///F1 key
        ///</summary>
        F1 = 0x70,
        ///<summary>
        ///F2 key
        ///</summary>
        F2 = 0x71,
        ///<summary>
        ///F3 key
        ///</summary>
        F3 = 0x72,
        ///<summary>
        ///F4 key
        ///</summary>
        F4 = 0x73,
        ///<summary>
        ///F5 key
        ///</summary>
        F5 = 0x74,
        ///<summary>
        ///F6 key
        ///</summary>
        F6 = 0x75,
        ///<summary>
        ///F7 key
        ///</summary>
        F7 = 0x76,
        ///<summary>
        ///F8 key
        ///</summary>
        F8 = 0x77,
        ///<summary>
        ///F9 key
        ///</summary>
        F9 = 0x78,
        ///<summary>
        ///F10 key
        ///</summary>
        F10 = 0x79,
        ///<summary>
        ///F11 key
        ///</summary>
        F11 = 0x7A,
        ///<summary>
        ///F12 key
        ///</summary>
        F12 = 0x7B,
        ///<summary>
        ///F13 key
        ///</summary>
        F13 = 0x7C,
        ///<summary>
        ///F14 key
        ///</summary>
        F14 = 0x7D,
        ///<summary>
        ///F15 key
        ///</summary>
        F15 = 0x7E,
        ///<summary>
        ///F16 key
        ///</summary>
        F16 = 0x7F,
        ///<summary>
        ///F17 key  
        ///</summary>
        F17 = 0x80,
        ///<summary>
        ///F18 key  
        ///</summary>
        F18 = 0x81,
        ///<summary>
        ///F19 key  
        ///</summary>
        F19 = 0x82,
        ///<summary>
        ///F20 key  
        ///</summary>
        F20 = 0x83,
        ///<summary>
        ///F21 key  
        ///</summary>
        F21 = 0x84,
        ///<summary>
        ///F22 key, (PPC only) Key used to lock device.
        ///</summary>
        F22 = 0x85,
        ///<summary>
        ///F23 key  
        ///</summary>
        F23 = 0x86,
        ///<summary>
        ///F24 key  
        ///</summary>
        F24 = 0x87,
        ///<summary>
        ///NUM LOCK key
        ///</summary>
        NUMLOCK = 0x90,
        ///<summary>
        ///SCROLL LOCK key
        ///</summary>
        SCROLL = 0x91,
        ///<summary>
        ///Left SHIFT key
        ///</summary>
        LSHIFT = 0xA0,
        ///<summary>
        ///Right SHIFT key
        ///</summary>
        RSHIFT = 0xA1,
        ///<summary>
        ///Left CONTROL key
        ///</summary>
        LCONTROL = 0xA2,
        ///<summary>
        ///Right CONTROL key
        ///</summary>
        RCONTROL = 0xA3,
        ///<summary>
        ///Left MENU key
        ///</summary>
        LMENU = 0xA4,
        ///<summary>
        ///Right MENU key
        ///</summary>
        RMENU = 0xA5,
        ///<summary>
        ///Windows 2000/XP: Browser Back key
        ///</summary>
        BROWSER_BACK = 0xA6,
        ///<summary>
        ///Windows 2000/XP: Browser Forward key
        ///</summary>
        BROWSER_FORWARD = 0xA7,
        ///<summary>
        ///Windows 2000/XP: Browser Refresh key
        ///</summary>
        BROWSER_REFRESH = 0xA8,
        ///<summary>
        ///Windows 2000/XP: Browser Stop key
        ///</summary>
        BROWSER_STOP = 0xA9,
        ///<summary>
        ///Windows 2000/XP: Browser Search key 
        ///</summary>
        BROWSER_SEARCH = 0xAA,
        ///<summary>
        ///Windows 2000/XP: Browser Favorites key
        ///</summary>
        BROWSER_FAVORITES = 0xAB,
        ///<summary>
        ///Windows 2000/XP: Browser Start and Home key
        ///</summary>
        BROWSER_HOME = 0xAC,
        ///<summary>
        ///Windows 2000/XP: Volume Mute key
        ///</summary>
        VOLUME_MUTE = 0xAD,
        ///<summary>
        ///Windows 2000/XP: Volume Down key
        ///</summary>
        VOLUME_DOWN = 0xAE,
        ///<summary>
        ///Windows 2000/XP: Volume Up key
        ///</summary>
        VOLUME_UP = 0xAF,
        ///<summary>
        ///Windows 2000/XP: Next Track key
        ///</summary>
        MEDIA_NEXT_TRACK = 0xB0,
        ///<summary>
        ///Windows 2000/XP: Previous Track key
        ///</summary>
        MEDIA_PREV_TRACK = 0xB1,
        ///<summary>
        ///Windows 2000/XP: Stop Media key
        ///</summary>
        MEDIA_STOP = 0xB2,
        ///<summary>
        ///Windows 2000/XP: Play/Pause Media key
        ///</summary>
        MEDIA_PLAY_PAUSE = 0xB3,
        ///<summary>
        ///Windows 2000/XP: Start Mail key
        ///</summary>
        LAUNCH_MAIL = 0xB4,
        ///<summary>
        ///Windows 2000/XP: Select Media key
        ///</summary>
        LAUNCH_MEDIA_SELECT = 0xB5,
        ///<summary>
        ///Windows 2000/XP: Start Application 1 key
        ///</summary>
        LAUNCH_APP1 = 0xB6,
        ///<summary>
        ///Windows 2000/XP: Start Application 2 key
        ///</summary>
        LAUNCH_APP2 = 0xB7,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_1 = 0xBA,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '+' key
        ///</summary>
        OEM_PLUS = 0xBB,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the ',' key
        ///</summary>
        OEM_COMMA = 0xBC,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '-' key
        ///</summary>
        OEM_MINUS = 0xBD,
        ///<summary>
        ///Windows 2000/XP: For any country/region, the '.' key
        ///</summary>
        OEM_PERIOD = 0xBE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_2 = 0xBF,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_3 = 0xC0,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_4 = 0xDB,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_5 = 0xDC,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_6 = 0xDD,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard. 
        ///</summary>
        OEM_7 = 0xDE,
        ///<summary>
        ///Used for miscellaneous characters; it can vary by keyboard.
        ///</summary>
        OEM_8 = 0xDF,
        ///<summary>
        ///Windows 2000/XP: Either the angle bracket key or the backslash key on the RT 102-key keyboard
        ///</summary>
        OEM_102 = 0xE2,
        ///<summary>
        ///Windows 95/98/Me, Windows NT 4.0, Windows 2000/XP: IME PROCESS key
        ///</summary>
        PROCESSKEY = 0xE5,
        ///<summary>
        ///Windows 2000/XP: Used to pass Unicode characters as if they were keystrokes.
        ///The VK_PACKET key is the low word of a 32-bit Virtual Key value used for non-keyboard input methods. For more information,
        ///see Remark in KEYBDINPUT, SendInput, WM_KEYDOWN, and WM_KEYUP
        ///</summary>
        PACKET = 0xE7,
        ///<summary>
        ///Attn key
        ///</summary>
        ATTN = 0xF6,
        ///<summary>
        ///CrSel key
        ///</summary>
        CRSEL = 0xF7,
        ///<summary>
        ///ExSel key
        ///</summary>
        EXSEL = 0xF8,
        ///<summary>
        ///Erase EOF key
        ///</summary>
        EREOF = 0xF9,
        ///<summary>
        ///Play key
        ///</summary>
        PLAY = 0xFA,
        ///<summary>
        ///Zoom key
        ///</summary>
        ZOOM = 0xFB,
        ///<summary>
        ///Reserved 
        ///</summary>
        NONAME = 0xFC,
        ///<summary>
        ///PA1 key
        ///</summary>
        PA1 = 0xFD,
        ///<summary>
        ///Clear key
        ///</summary>
        OEM_CLEAR = 0xFE
    }

    public enum ScanCodeShort : short
    {
        LBUTTON = 0,
        RBUTTON = 0,
        CANCEL = 70,
        MBUTTON = 0,
        XBUTTON1 = 0,
        XBUTTON2 = 0,
        BACK = 14,
        TAB = 15,
        CLEAR = 76,
        RETURN = 28,
        SHIFT = 42,
        CONTROL = 29,
        MENU = 56,
        PAUSE = 0,
        CAPITAL = 58,
        KANA = 0,
        HANGUL = 0,
        JUNJA = 0,
        FINAL = 0,
        HANJA = 0,
        KANJI = 0,
        ESCAPE = 1,
        CONVERT = 0,
        NONCONVERT = 0,
        ACCEPT = 0,
        MODECHANGE = 0,
        SPACE = 57,
        PRIOR = 73,
        NEXT = 81,
        END = 79,
        HOME = 71,
        LEFT = 75,
        UP = 72,
        RIGHT = 77,
        DOWN = 80,
        SELECT = 0,
        PRINT = 0,
        EXECUTE = 0,
        SNAPSHOT = 84,
        INSERT = 82,
        DELETE = 83,
        HELP = 99,
        KEY_0 = 11,
        KEY_1 = 2,
        KEY_2 = 3,
        KEY_3 = 4,
        KEY_4 = 5,
        KEY_5 = 6,
        KEY_6 = 7,
        KEY_7 = 8,
        KEY_8 = 9,
        KEY_9 = 10,
        KEY_A = 30,
        KEY_B = 48,
        KEY_C = 46,
        KEY_D = 32,
        KEY_E = 18,
        KEY_F = 33,
        KEY_G = 34,
        KEY_H = 35,
        KEY_I = 23,
        KEY_J = 36,
        KEY_K = 37,
        KEY_L = 38,
        KEY_M = 50,
        KEY_N = 49,
        KEY_O = 24,
        KEY_P = 25,
        KEY_Q = 16,
        KEY_R = 19,
        KEY_S = 31,
        KEY_T = 20,
        KEY_U = 22,
        KEY_V = 47,
        KEY_W = 17,
        KEY_X = 45,
        KEY_Y = 21,
        KEY_Z = 44,
        LWIN = 91,
        RWIN = 92,
        APPS = 93,
        SLEEP = 95,
        NUMPAD0 = 82,
        NUMPAD1 = 79,
        NUMPAD2 = 80,
        NUMPAD3 = 81,
        NUMPAD4 = 75,
        NUMPAD5 = 76,
        NUMPAD6 = 77,
        NUMPAD7 = 71,
        NUMPAD8 = 72,
        NUMPAD9 = 73,
        MULTIPLY = 55,
        ADD = 78,
        SEPARATOR = 0,
        SUBTRACT = 74,
        DECIMAL = 83,
        DIVIDE = 53,
        F1 = 59,
        F2 = 60,
        F3 = 61,
        F4 = 62,
        F5 = 63,
        F6 = 64,
        F7 = 65,
        F8 = 66,
        F9 = 67,
        F10 = 68,
        F11 = 87,
        F12 = 88,
        F13 = 100,
        F14 = 101,
        F15 = 102,
        F16 = 103,
        F17 = 104,
        F18 = 105,
        F19 = 106,
        F20 = 107,
        F21 = 108,
        F22 = 109,
        F23 = 110,
        F24 = 118,
        NUMLOCK = 69,
        SCROLL = 70,
        LSHIFT = 42,
        RSHIFT = 54,
        LCONTROL = 29,
        RCONTROL = 29,
        LMENU = 56,
        RMENU = 56,
        BROWSER_BACK = 106,
        BROWSER_FORWARD = 105,
        BROWSER_REFRESH = 103,
        BROWSER_STOP = 104,
        BROWSER_SEARCH = 101,
        BROWSER_FAVORITES = 102,
        BROWSER_HOME = 50,
        VOLUME_MUTE = 32,
        VOLUME_DOWN = 46,
        VOLUME_UP = 48,
        MEDIA_NEXT_TRACK = 25,
        MEDIA_PREV_TRACK = 16,
        MEDIA_STOP = 36,
        MEDIA_PLAY_PAUSE = 34,
        LAUNCH_MAIL = 108,
        LAUNCH_MEDIA_SELECT = 109,
        LAUNCH_APP1 = 107,
        LAUNCH_APP2 = 33,
        OEM_1 = 39,
        OEM_PLUS = 13,
        OEM_COMMA = 51,
        OEM_MINUS = 12,
        OEM_PERIOD = 52,
        OEM_2 = 53,
        OEM_3 = 41,
        OEM_4 = 26,
        OEM_5 = 43,
        OEM_6 = 27,
        OEM_7 = 40,
        OEM_8 = 0,
        OEM_102 = 86,
        PROCESSKEY = 0,
        PACKET = 0,
        ATTN = 0,
        CRSEL = 0,
        EXSEL = 0,
        EREOF = 93,
        PLAY = 0,
        ZOOM = 98,
        NONAME = 0,
        PA1 = 0,
        OEM_CLEAR = 0,
    }

    /// <summary>
    /// Define HARDWAREINPUT struct
    /// </summary>
    [StructLayout(LayoutKind.Sequential)]
    public struct HARDWAREINPUT
    {
        internal int uMsg;
        internal short wParamL;
        internal short wParamH;
    }
}