/// <summary>
/// Private hook that checks the return code
/// and calls the overridden hook process <paramref name="hookProc"/>
/// </summary>
/// <param name="code">A code the hook procedure uses to determine
/// how to process the message.</param>
/// <param name="wParam">The virtual-key code of the key that generated
/// the keystroke message.</param>
/// <param name="lParam">The repeat count, scan code, extended-key flag,
/// context code, previous key-state flag,</param>
/// <see cref="https://msdn.microsoft.com/en-us/library/windows/desktop/ms644984%28v=vs.85%29.aspx"/>
/// <returns></returns>
private int _hookProc(int code, int wParam, ref KeyboardHookData lParam)
{
if (code >= 0)
{
//Pass on for other objects to process.
/*return*/ this.hookProc(code, wParam, ref lParam);
}
//else
return(CallNextHookEx(hhook, code, wParam, ref lParam));
}
/// <summary>
/// Overridable function called by the hooked procedure
/// function <typeparamref name="_hookProc"/>.
/// </summary>
/// <param name="code">A code the hook procedure uses to determine
/// how to process the message.</param>
/// <param name="wParam">The virtual-key code of the key that generated
/// the keystroke message.</param>
/// <param name="lParam">The repeat count, scan code, extended-key flag,
/// context code, previous key-state flag,</param>
/// <see cref="https://msdn.microsoft.com/en-us/library/windows/desktop/ms644984%28v=vs.85%29.aspx"/>
/// <returns></returns>
public virtual int hookProc(
int code, int wParam, ref KeyboardHookData lParam)
{
Keys k = (Keys)lParam.vkCode;
//Check for shift(s), alt, and ctrl.
//Shift
if (k == Keys.LShiftKey)
{
bLeftShiftHeld = bShiftHeld = (wParam == WM_KEYDOWN);
}
else if (k == Keys.RShiftKey)
{
bRightShiftHeld = bShiftHeld = (wParam == WM_KEYDOWN);
}
//Control
if ((lParam.vkCode & 0xA2) == 0xA2 || (lParam.vkCode & 0xA3) == 0xA3)
{
bCtrlHeld = (wParam == WM_KEYDOWN);
return(1);
}
//Alt
if ((lParam.vkCode & 0xA4) == 0xA4 || (lParam.vkCode & 0xA5) == 0xA5)
{
bAltHeld = (wParam == WM_KEYDOWN);
return(1);
}
//Win
if (lParam.vkCode == 0x5B)
{
bWinHeld = (wParam == WM_KEYDOWN);
return(1);
}
//Key Press Event
KeyEventArgs kea = new KeyEventArgs(k);
if ((wParam == WM_KEYDOWN || wParam == WM_SYSKEYDOWN) && (KeyDown != null))
{
KeyDown(wParam, lParam);
}
else if ((wParam == WM_KEYUP || wParam == WM_SYSKEYUP) && (KeyUp != null))
{
KeyUp(wParam, lParam);
}
if (kea.Handled)
{
return(1);
}
return(CallNextHookEx(hhook, code, wParam, ref lParam));
}
static extern int CallNextHookEx(IntPtr idHook, int nCode, int wParam, ref KeyboardHookData lParam);