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 [DllImport("user32.dll")]
        private static extern IntPtr SetWindowsHookEx(HookType code, HookProc func, IntPtr hInstance, int threadID);

        [DllImport("user32.dll")]
        private static extern int CallNextHookEx(IntPtr hhk, int nCode, IntPtr wParam, IntPtr lParam);

        private delegate int HookProc(int code, IntPtr wParam, IntPtr lParam);
        private HookProc myCallbackDelegate = null;

        public enum HookType : int
        {
            WH_JOURNALRECORD = 0,
            WH_JOURNALPLAYBACK = 1,
            WH_KEYBOARD = 2,
            WH_GETMESSAGE = 3,
            WH_CALLWNDPROC = 4,
            WH_CBT = 5,
            WH_SYSMSGFILTER = 6,
            WH_MOUSE = 7,
            WH_HARDWARE = 8,
            WH_DEBUG = 9,
            WH_SHELL = 10,
            WH_FOREGROUNDIDLE = 11,
            WH_CALLWNDPROCRET = 12,
            WH_KEYBOARD_LL = 13,
            WH_MOUSE_LL = 14
        }


 public Form1()
        {
            InitializeComponent();
            
            // initialize our delegate
            this.myCallbackDelegate = new HookProc(this.KeyPressed);

            // setup a global gui-thread mouse hook
            SetWindowsHookEx(HookType.WH_KEYBOARD, this.myCallbackDelegate, IntPtr.Zero, AppDomain.GetCurrentThreadId());
        
        }



 private int KeyPressed(int code, IntPtr wParam, IntPtr lParam)
        {
            if (code < 0) return CallNextHookEx(IntPtr.Zero, code, wParam, lParam);
            int i = wParam.ToInt32();
            if (i >= 112 && i <= 123)
            {
                //112 = f1, 113=f2, usw
               i -= 111;
                abspielen(i);
            }
            
            //return the value returned by CallNextHookEx
            return CallNextHookEx(IntPtr.Zero, code, wParam, lParam);
        }