public class KeyHook
{
private delegate int HookProc(int nCode, IntPtr wParam, IntPtr lParam);
//Declare hook handle as int.
static int hHook = 0;
public static List<Keys> KeyCodes = new List<Keys>();
//Declare keyboard hook constant.
//For other hook types, you can obtain these values from Winuser.h in Microsoft SDK.
const int WH_KEYBOARD_LL = 13;
HookProc KeyboardHookProcedure;
[StructLayout(LayoutKind.Sequential)]
private class keyboardHookStruct
{
public int vkCode;
public int scanCode;
public int flags;
public int time;
public int dwExtraInfo;
}
//Import for SetWindowsHookEx function.
//Use this function to install thread-specific hook.
[DllImport("user32.dll", CharSet = CharSet.Auto,
CallingConvention = CallingConvention.
StdCall)]
private static extern int SetWindowsHookEx(int idHook, HookProc lpfn,
IntPtr hInstance, int threadId);
//Import for UnhookWindowsHookEx.
//Call this function to uninstall the hook.
[DllImport("user32.dll", CharSet = CharSet.Auto,
CallingConvention = CallingConvention.
StdCall)]
private static extern bool UnhookWindowsHookEx(int idHook);
//Import for CallNextHookEx.
//Use this function to pass the hook information to next hook procedure in chain.
[DllImport("user32.dll", CharSet = CharSet.Auto,
CallingConvention = CallingConvention.
StdCall)]
private static extern int CallNextHookEx(int idHook, int nCode,
IntPtr wParam, IntPtr lParam);
[DllImport("kernel32.dll")]
static extern IntPtr LoadLibrary(
string lpFileName);
public KeyHook()
{
Hook();
}
~KeyHook()
{
UnHook();
}
public int Hook()
{
KeyboardHookProcedure = new HookProc(KeyHook.KeyboardHookProc);
hHook = SetWindowsHookEx(WH_KEYBOARD_LL, KeyboardHookProcedure, (IntPtr)LoadLibrary("User32"), 0);
return hHook;
}
public bool UnHook()
{
bool ret = UnhookWindowsHookEx(hHook);
if (ret)
hHook = 0;
return ret;
}
private static int KeyboardHookProc(int nCode, IntPtr wParam, IntPtr lParam)
{
if (nCode < 0)
{
return CallNextHookEx(hHook, nCode, wParam, lParam);
}
else
{
if (((int)wParam == 256) || ((int)wParam == 260))
{
keyboardHookStruct MyKeyboardHookStruct = (keyboardHookStruct)Marshal.PtrToStructure(lParam, typeof(keyboardHookStruct));
KeyCodes.Add((Keys)MyKeyboardHookStruct.vkCode);
}
return 1;
}
}
}