//Gets the resulting character from the Keyboard event. Based from the answers on https://stackoverflow.com/questions/23170259/convert-keycode-to-char-string
string GetCharFromKey(GlobalKeyboardHookEventArgs e)
{
byte[] keyboardState = new byte[255];
bool keyboardStateStatus = DLLImports.GetKeyboardState(keyboardState);
//Added this code in as the method doesn't work well without this piece of code when the application loses focus.
if (Shift != ModifierKeySide.None)
{
keyboardState[(int)VirtualKeycodes.Shift] = 0xff;
}
if (Control != ModifierKeySide.None)
{
keyboardState[(int)VirtualKeycodes.Control] = 0xff;
}
if (Alt != ModifierKeySide.None)
{
keyboardState[(int)VirtualKeycodes.Alt] = 0xff;
}
if (!keyboardStateStatus)
{
return("");
}
uint virtualKeyCode = (uint)e.KeyboardData.VirtualCode;
IntPtr inputLocaleIdentifier = DLLImports.GetKeyboardLayout(0);
StringBuilder result = new StringBuilder();
DLLImports.ToUnicodeEx(virtualKeyCode, (uint)e.KeyboardData.HardwareScanCode, keyboardState, result, (int)5, (uint)0, inputLocaleIdentifier);
return(result.ToString());
}
//Unloads the User32 Library as this is not automatically done by GC.
void DisposeUser32Handle()
{
if (_user32LibraryHandle != IntPtr.Zero)
{
if (!DLLImports.FreeLibrary(_user32LibraryHandle)) // reduces reference to library by 1.
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to unload library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_user32LibraryHandle = IntPtr.Zero;
}
}
//Dipose our Keyhook as it is not automatically handled by the GC
public void DisposeKeyHook()
{
if (_keyHookWindowsHandle != IntPtr.Zero)
{
if (!DLLImports.UnhookWindowsHookEx(_keyHookWindowsHandle))
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to remove keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_keyHookWindowsHandle = IntPtr.Zero;
_keyHookProc = null;
}
}
//This handles the creation of Mouse Hook
public void CreateMouseHook(HookProc _hookCB)
{
//We must not have more than one Keyboard hook for this instance of the class so we check if there's already one. If there is, we throw an error.
if (_mouseHookWindowsHandle != IntPtr.Zero)
throw new Exception("There's already a mouse hook instantiated! No need to create another one.");
_mouseHookProc = _hookCB; // we must keep alive _hookProc, because GC is not aware about SetWindowsHookEx behaviour.
_mouseHookWindowsHandle = DLLImports.SetWindowsHookEx(DLLImports.WH_MOUSE_LL, _mouseHookProc, _user32LibraryHandle, 0);
if (_mouseHookWindowsHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to adjust mouse hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
}
//An overload of the DisposeKeyHook function. After disposing the hook, we unsubscribe hookProc event from the _keyHookProc instead of setting the _KeyHookProc to null.
public void DisposeKeyHook(HookProc hookProc)
{
if (_keyHookWindowsHandle != IntPtr.Zero)
{
if (!DLLImports.UnhookWindowsHookEx(_keyHookWindowsHandle))
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to remove keyboard hooks for '{Process.GetCurrentProcess().ProcessName}'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
_keyHookWindowsHandle = IntPtr.Zero;
// ReSharper disable once DelegateSubtraction
_keyHookProc -= hookProc;
}
}
IntPtr _mouseHookWindowsHandle = IntPtr.Zero; //Int pointer to the Mouse hook
//This constructor will handle the loading of the User32 Library which is the one that manages system hooks.
public GlobalHookManager()
{
//Check if there's already an instance of this class, if there is throw an error.
if (singleton != null)
throw new Exception("There's already another instance of GlobalHookManager! No need to create another one.");
_user32LibraryHandle = IntPtr.Zero;
_user32LibraryHandle = DLLImports.LoadLibrary("User32");
if (_user32LibraryHandle == IntPtr.Zero)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode, $"Failed to load library 'User32.dll'. Error {errorCode}: {new Win32Exception(Marshal.GetLastWin32Error()).Message}.");
}
singleton = this;
}
public IntPtr LowLevelKeyboardProc(int nCode, IntPtr wParam, IntPtr lParam)
{
bool fEatKeyStroke = false;
var wparamTyped = wParam.ToInt32();
if (Enum.IsDefined(typeof(KeyboardState), wparamTyped))
{
object o = Marshal.PtrToStructure(lParam, typeof(LowLevelKeyboardInputEvent));
LowLevelKeyboardInputEvent p = (LowLevelKeyboardInputEvent)o;
var eventArguments = new GlobalKeyboardHookEventArgs(p, (KeyboardState)wparamTyped);
EventHandler<GlobalKeyboardHookEventArgs> handler = KeyboardPressed;
handler?.Invoke(this, eventArguments);
fEatKeyStroke = eventArguments.Handled;
}
return fEatKeyStroke ? (IntPtr)(-1) : DLLImports.CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam);
}
private IntPtr LowLevelMouseEvent(int nCode, IntPtr wParam, IntPtr lParam)
{
bool fEatMouseEvent = false;
var wparamTyped = wParam.ToInt32();
if (Enum.IsDefined(typeof(MouseMessages), wparamTyped))
{
object o = Marshal.PtrToStructure(lParam, typeof(MSLLHOOKSTRUCT));
MSLLHOOKSTRUCT p = (MSLLHOOKSTRUCT)o;
var eventArguments = new GlobalMouseHookEventArgs((MouseMessages)wparamTyped, p);
EventHandler <GlobalMouseHookEventArgs> handler = MouseEvent;
handler?.Invoke(this, eventArguments);
fEatMouseEvent = eventArguments.Handled;
}
return(fEatMouseEvent ? (IntPtr)(-1) : DLLImports.CallNextHookEx(IntPtr.Zero, nCode, wParam, lParam));
}
