/// <summary>Initializes the keyboard hook.</summary>
/// <param name="keyDown">The delegate to be called when a key down event occurs.</param>
public KeyboardHook(int targetProcessID, KeyEventHandler keyDown)
{
if (keyDown == null)
{
throw new ArgumentNullException("keyDown");
}
// Store the user's KeyDown delegate
_keyDown = keyDown;
_pid = targetProcessID;
// Create the callback and pin it, since it'll be called
// from unmanaged code
_hookProc = new LowLevelKeyboardProc(HookCallback);
// Set the hook for just the GUI thread
using (Process curProcess = Process.GetCurrentProcess())
using (ProcessModule curModule = curProcess.MainModule)
{
_hookHandle = SafeWindowsHookHandle.SetWindowsHookEx(
WH_KEYBOARD_LL, _hookProc,
GetModuleHandle(curModule.ModuleName), 0);
}
if (_hookHandle.IsInvalid)
{
Exception exc = new Win32Exception();
Dispose();
throw exc;
}
}
/// <summary>Callback from the installed hook.</summary>
///</returns>
private IntPtr HookCallback(int nCode, IntPtr wParam, IntPtr lParam)
{
bool handled = false;
try
{
if (nCode >= 0 && wParam == (IntPtr)WM_KEYDOWN)
{
uint pid;
GetWindowThreadProcessId(GetForegroundWindow(), out pid);
if (pid == _pid)
{
KBDLLHOOKSTRUCT hookParam =
(KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lParam,
typeof(KBDLLHOOKSTRUCT));
Keys key = (Keys)hookParam.vkCode;
if (key == Keys.Packet)
{
key = (Keys)hookParam.scanCode;
}
KeyEventArgs e = new KeyEventArgs(key | ModifierKeys);
_keyDown(this, e);
handled = e.Handled | e.SuppressKeyPress;
}
}
// won't work because WH_KEYBOARD_LL doesn't fire for app commands
// can't change it to WH_SHELL to get the app commands to fire because
// only WH_KEYBOARD_LL and WH_MOUSE_LL are supported for global hooks like this one
else if (nCode >= 0 && wParam == (IntPtr)WM_APPCOMMAND)
{
// LogToFile("app command detected");
uint pid;
GetWindowThreadProcessId(GetForegroundWindow(), out pid);
if (pid == _pid)
{
int cmd = (int)((uint)lParam >> 16 & ~0xf000);
// LogToFile("app command is " + cmd);
Keys key = Keys.F24;
if (cmd == APPCOMMAND_MEDIA_PLAY)
{
key = Keys.Play;
}
KeyEventArgs e = new KeyEventArgs(key | ModifierKeys);
_keyDown(this, e);
handled = e.Handled | e.SuppressKeyPress;
}
}
return(handled ?
new IntPtr(1) :
SafeWindowsHookHandle.CallNextHookEx(
_hookHandle, nCode, wParam, lParam));
}
catch (Exception exc) { Error(this, new ErrorEventArgs(exc)); }
return(new IntPtr(1));
}
/// <summary>Dispose the KeyboardHook.</summary>
public void Dispose()
{
if (_hookHandle != null)
{
_hookHandle.Dispose();
_hookHandle = null;
}
}
public static extern IntPtr CallNextHookEx(SafeWindowsHookHandle hhk, int nCode, IntPtr wParam, IntPtr lParam);