C# hold key in a game application

Question

I'm trying to make a C# application, which is going to control a game. That I'm trying to do is for example: Hold key A for 150ms, Hold left arrow for 500ms and so on. I was searching a lot and I found the following code. My program firstly target the game and then holding the keys.

I'm holding the keys this way:

Keyboard.HoldKey(Keys.Left);
Thread.sleep(500);
Keyboard.ReleaseKey(Keys.Left);

Here is the Keyboard class:

public class Keyboard
 {
    public Keyboard()
    {
    }

    [StructLayout(LayoutKind.Explicit, Size = 28)]
    public struct Input
    {
        [FieldOffset(0)]
        public uint type;
        [FieldOffset(4)]
        public KeyboardInput ki;
    }

    public struct KeyboardInput
    {
        public ushort wVk;
        public ushort wScan;
        public uint dwFlags;
        public long time;
        public uint dwExtraInfo;
    }

    const int KEYEVENTF_KEYUP = 0x0002;
    const int INPUT_KEYBOARD = 1;

    [DllImport("user32.dll")]
    public static extern int SendInput(uint cInputs, ref Input inputs, int cbSize);

    [DllImport("user32.dll")]
    static extern short GetKeyState(int nVirtKey);

    [DllImport("user32.dll")]
    static extern ushort MapVirtualKey(int wCode, int wMapType);


    public static bool IsKeyDown(Keys key)
    {
        return (GetKeyState((int)key) & -128) == -128;
    }

    public static void HoldKey(Keys vk)
    {
        ushort nScan = MapVirtualKey((ushort)vk, 0);

        Input input = new Input();
        input.type = INPUT_KEYBOARD;
        input.ki.wVk = (ushort)vk;
        input.ki.wScan = nScan;
        input.ki.dwFlags = 0;
        input.ki.time = 0;
        input.ki.dwExtraInfo = 0;
        SendInput(1, ref input, Marshal.SizeOf(input)).ToString();
    }

    public static void ReleaseKey(Keys vk)
    {
        ushort nScan = MapVirtualKey((ushort)vk, 0);

        Input input = new Input();
        input.type = INPUT_KEYBOARD;
        input.ki.wVk = (ushort)vk;
        input.ki.wScan = nScan;
        input.ki.dwFlags = KEYEVENTF_KEYUP;
        input.ki.time = 0;
        input.ki.dwExtraInfo = 0;
        SendInput(1, ref input, Marshal.SizeOf(input));
    }

    public static void PressKey(Keys vk)
    {
        HoldKey(vk);
        ReleaseKey(vk);
    }
}

and its working in notepad/browser etc, but it IS NOT working in any game, no matter fullscreen or window mode. Can you help me to figure out how I can hold keys in full screen apps/games? Thanks!

You can't just google a piece of code, dump it into an app and expect it to work. Define `not working`? It's a very broad term, what exactly isn't working? — DGibbs, May 02 '13 at 16:02
Games normally aquire keyboard via DirectX which is a very different way of handling. Sending Windows input messages to such apps is not useful. [E.g.](http://courses.washington.edu/css450/2008.Fall/web_contents/from_students/450Hints/DirectInputTutorial/DirectInputTutorial.pdf) [PDF]. — GSerg, May 02 '13 at 16:05
Well I did everything else by myself, just I'm not used to windows API. By not working I mean my application is targeting the game and trying to hold/release the arrow game, but nothing happens ingame. If I press the arrow on my keyboard it works. — Deepsy, May 02 '13 at 16:07
@GSerg can you give me a little example, how I should be able to do that? — Deepsy, May 02 '13 at 16:09

Idle_Mind · Answer 1 · 2013-05-02T16:52:08.993

4

"Hold key A for 150ms, Hold left arrow for 500ms"

See if this works:

        Keyboard.HoldKey((byte)Keys.A, 150);
        Keyboard.HoldKey((byte)Keys.Left, 500);

Using:

public class Keyboard
{
    [DllImport("user32.dll", SetLastError = true)]
    static extern void keybd_event(byte bVk, byte bScan, int dwFlags, int dwExtraInfo);

    const int KEY_DOWN_EVENT = 0x0001; //Key down flag
    const int KEY_UP_EVENT = 0x0002; //Key up flag

    public static void HoldKey(byte key, int duration)
    {
        int totalDuration = 0;
        while (totalDuration < duration)
        {
            keybd_event(key, 0, KEY_DOWN_EVENT, 0);
            keybd_event(key, 0, KEY_UP_EVENT, 0);
            System.Threading.Thread.Sleep(PauseBetweenStrokes);
            totalDuration += PauseBetweenStrokes;
        }
    }
}

edited May 02 '13 at 16:52

answered May 02 '13 at 16:25

Idle_Mind

35,854
3
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Hello. Thanks for the answer, but sadly the effect is the same as code posted in my first post: its working in notepad/browsers etc, but its not working in game windows. – Deepsy May 02 '13 at 16:35
I changed HoldKey() to rapidly press/release the key until duration has been met. See if that works any better... – Idle_Mind May 02 '13 at 16:52
Still the same, Seems the game are handling the key pressed in different way :( – Deepsy May 02 '13 at 17:15
Just noticed I didn't include "PauseBetweenStrokes": `const int PauseBetweenStrokes = 50;` I don't think it will make much difference, though. Sorry it didn't work...good luck! – Idle_Mind May 02 '13 at 17:21
Yeah, I tried with 1, 10 and 20 :( Seems not every game is able to handle such operations. – Deepsy May 02 '13 at 17:25
Supposedly these guys got SendInput() working with DirectInput [here](http://stackoverflow.com/questions/3644881/simulating-keyboard-with-sendinput-api-in-directinput-applications). – Idle_Mind May 02 '13 at 17:32

score 2 · Answer 2 · answered Aug 21 '15 at 14:10

You can get it to work with that, this works great for holding down keys:

    public class Keyboard
{

    const int PauseBetweenStrokes = 50;
    [DllImport("user32.dll", SetLastError = true)]
    static extern void keybd_event(byte bVk, byte bScan, int dwFlags, int dwExtraInfo);

    const int KEY_DOWN_EVENT = 0x0001; //Key down flag
    const int KEY_UP_EVENT = 0x0002; //Key up flag

    public static void HoldKey(byte key, int duration)
    {
        keybd_event(key, 0, KEY_DOWN_EVENT, 0);
        System.Threading.Thread.Sleep(duration);
        keybd_event(key, 0, KEY_UP_EVENT, 0);
    }
}

score 0 · Accepted Answer · answered May 04 '13 at 13:37

0

I did it with Windown API and SendInput method.

answered May 04 '13 at 13:37

Deepsy

3,658
6
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Can you explain what you mean by this? – SJ10 May 25 '21 at 19:18

C# hold key in a game application

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