/// <summary>Determines whether the specified keyboard input should be allowed to be processed by the system.</summary>
/// <remarks>Helps block unwanted keys and key combinations that could exit the app, make system changes, etc.</remarks>
public static bool AllowKeyboardInput(bool alt, bool control, Keyboard.VirtualKeyStates key)
{
// Disallow various special keys.
if (key <= Keyboard.VirtualKeyStates.VK_BACK || key == Keyboard.VirtualKeyStates.VK_NONAME ||
key == Keyboard.VirtualKeyStates.VK_MENU || key == Keyboard.VirtualKeyStates.VK_PAUSE ||
key == Keyboard.VirtualKeyStates.VK_HELP)
{
return(false);
}
// Disallow ranges of special keys.
// Currently leaves volume controls enabled; consider if this makes sense.
// Disables non-existing Keys up to 65534, to err on the side of caution for future keyboard expansion.
if ((key >= Keyboard.VirtualKeyStates.VK_LWIN && key <= Keyboard.VirtualKeyStates.VK_SLEEP) ||
(key >= Keyboard.VirtualKeyStates.VK_KANA && key <= Keyboard.VirtualKeyStates.VK_HANJA) ||
(key >= Keyboard.VirtualKeyStates.VK_CONVERT && key <= Keyboard.VirtualKeyStates.VK_MODECHANGE) ||
//(key >= VirtualKey.BROWSER_BACK && key <= VirtualKey.BROWSER_HOME) ||
(key >= Keyboard.VirtualKeyStates.VK_MEDIA_NEXT_TRACK && key <= Keyboard.VirtualKeyStates.VK_LAUNCH_APP2) ||
(key >= Keyboard.VirtualKeyStates.VK_PROCESSKEY && key <= (Keyboard.VirtualKeyStates) 65534))
{
return(false);
}
// Disallow specific key combinations. (These component keys would be OK on their own.)
if ((alt && key == Keyboard.VirtualKeyStates.VK_TAB) ||
(alt && key == Keyboard.VirtualKeyStates.VK_SPACE) ||
(control && key == Keyboard.VirtualKeyStates.VK_ESCAPE))
{
return(false);
}
// Allow anything else (like letters, numbers, spacebar, braces, and so on).
return(true);
}
private IntPtr KeyHookProc(int nCode, IntPtr wParam, IntPtr lParam)
{
Hook.KBDLLHOOKSTRUCT hs = (Hook.KBDLLHOOKSTRUCT)Marshal.PtrToStructure(lParam, typeof(Hook.KBDLLHOOKSTRUCT));
Message.WindowsMessage wm = (Message.WindowsMessage)wParam;
if (nCode >= 0 && (_key == 0 || _key == hs.vkCode))
{
Keyboard.VirtualKeyStates key = (Keyboard.VirtualKeyStates)hs.vkCode;
Keyboard.ScanCodes scanCode = (Keyboard.ScanCodes)hs.scanCode;
KeyboardState.KeyStatus status;
switch (wm)
{
case Message.WindowsMessage.KEYDOWN:
case Message.WindowsMessage.SYSKEYDOWN:
status = KeyboardState.KeyStatus.Down;
break;
case Message.WindowsMessage.KEYUP:
case Message.WindowsMessage.SYSKEYUP:
status = KeyboardState.KeyStatus.Up;
break;
default:
status = KeyboardState.KeyStatus.None;
break;
}
TimeSpan time = TimeSpan.FromMilliseconds(hs.time);
KeyboardState ks = KeyboardState.CreateCurrent(key, scanCode, status, time);
switch (ks.Status)
{
case KeyboardState.KeyStatus.Down:
KeyAny?.Invoke(this, ks);
KeyPress?.Invoke(this, ks);
KeyDown?.Invoke(this, ks);
break;
case KeyboardState.KeyStatus.Hold:
KeyAny?.Invoke(this, ks);
KeyPress?.Invoke(this, ks);
KeyHold?.Invoke(this, ks);
break;
case KeyboardState.KeyStatus.Up:
KeyAny?.Invoke(this, ks);
KeyUp?.Invoke(this, ks);
break;
default:
KeyAny?.Invoke(this, ks);
break;
}
if (CallNextHook is null || CallNextHook(this, ks))
{
return(Hook.CallNextHookEx(_kHHook, nCode, wParam, lParam));
}
else
{
return(_kHHook);
}
}
public static Keyboard.ScanCodes GetScanCode(Keyboard.VirtualKeyStates virtualKey)
{
if (Enum.TryParse((virtualKey & Keyboard.VirtualKeyStates.KeyCode).ToString(), out Keyboard.ScanCodes scanCode))
{
return(scanCode);
}
return(Keyboard.ScanCodes.None);
}
public KeyboardState(
Keyboard.VirtualKeyStates key = Keyboard.VirtualKeyStates.None,
Keyboard.ScanCodes scanCode = Keyboard.ScanCodes.None,
KeyStatus status = KeyStatus.None,
KeyModifiers modifiers = KeyModifiers.None,
TimeSpan time = new TimeSpan())
{
_Key = key;
_ScanCode = scanCode;
_Status = status;
_Modifiers = modifiers;
_Time = time;
}
public MouseState(
Keyboard.VirtualKeyStates key = Keyboard.VirtualKeyStates.None,
MouseStatus status = MouseStatus.None,
MouseModifiers modifiers = MouseModifiers.None,
int x = 0,
int y = 0,
int wheel = 0,
int hWheel = 0,
TimeSpan time = new TimeSpan())
{
_Key = key;
_Status = status;
_Modifiers = modifiers;
_X = x;
_Y = y;
_Wheel = wheel;
_HWheel = hWheel;
_Time = time;
}
public KeyboardHook(Keyboard.VirtualKeyStates vkCode = Keyboard.VirtualKeyStates.None)
{
_kProc = KeyHookProc;
_key = (int)vkCode;
}
public virtual void Up(Keyboard.VirtualKeyStates virtualKey, Keyboard.ScanCodes scanCode)
{
scanCode = GetClearScanCode(scanCode) | Keyboard.ScanCodes.Pressed | Keyboard.ScanCodes.Transition;
Message.PostMessage(WindowHandle, Message.WindowsMessage.KEYUP, (IntPtr)virtualKey, GetLParam(scanCode));
}
public void Hold(Keyboard.VirtualKeyStates virtualKey)
{
var scanCode = GetScanCode(virtualKey);
Hold(virtualKey, scanCode);
}
public virtual void Hold(Keyboard.VirtualKeyStates virtualKey, Keyboard.ScanCodes scanCode)
{
scanCode = GetClearScanCode(scanCode) | Keyboard.ScanCodes.Pressed;
Message.PostMessage(WindowHandle, Message.WindowsMessage.KEYDOWN, (IntPtr)virtualKey, GetLParam(scanCode));
}
public void Down(Keyboard.VirtualKeyStates virtualKey)
{
var scanCode = GetScanCode(virtualKey);
Down(virtualKey, scanCode);
}
public override void Down(Keyboard.VirtualKeyStates virtualKey, Keyboard.ScanCodes scanCode)
{
scanCode = GetClearScanCode(scanCode);
Message.PostMessage(WindowHandle, Message.WindowsMessage.SYSKEYDOWN, (IntPtr)virtualKey, GetLParam(scanCode));
}