private void ForceUnsunscribeFromForegroundChangedEvent()
{
if (s_ForegroundChangedHookHandle != 0)
{
bool result = WinApi.UnhookWinEvent(s_ForegroundChangedHookHandle);
s_ForegroundChangedHookHandle = 0;
s_ForegroundChangedDelegate = null;
if (result == false)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode);
}
}
}
private void EnsureSubscribeToForegroundChangedEvent()
{
if (s_ForegroundChangedHookHandle == 0)
{
s_ForegroundChangedDelegate = ForegroundChangedHookProc;
s_ForegroundChangedHookHandle = WinApi.SetWinEventHook(EventConstants.EVENT_SYSTEM_FOREGROUND, EventConstants.EVENT_SYSTEM_FOREGROUND, IntPtr.Zero, s_ForegroundChangedDelegate, 0, 0, WINEVENT_OUTOFCONTEXT);
if (s_ForegroundChangedHookHandle == 0)
{
int errorCode = Marshal.GetLastWin32Error();
throw new Win32Exception(errorCode);
}
}
}