public static void StartMonitoringActiveAppChangesIfNeeded()
{
if (ShouldMonitorActiveAppChange() && CurrentHook == IntPtr.Zero)
{
_handler = new WinEventHookProc(OnActiveWindowChanged);
CurrentHook = SetWinEventHook(EVENT_SYSTEM_FOREGROUND, EVENT_SYSTEM_FOREGROUND, IntPtr.Zero, _handler, 0, 0, WINEVENT_OUTOFCONTEXT);
}
}
static extern IntPtr SetWinEventHook(uint eventMin, uint eventMax, IntPtr hmodWinEventProc, WinEventHookProc lpfnWinEventProc, uint idProcess, uint idThread, uint dwFlags);