如何知道与流程关联的用户是否处于活动状态

Question

I use GetPixel to get colors of some points of Program Manager (desktop), however if the system is switched to another user, GetPixel always returns white .

So I need to know whether the user is active or the system is switched to another user.

A solution should work for OS: Windows XP till Windows 8.

This is what I do:

HWND ProgmanHwnd = FindWindow(L"Progman", L"Program Manager");
if (!ProgmanHwnd) return;
HDC hDC = GetWindowDC(ProgmanHwnd);
if (!hDC) return;
COLORREF color = GetPixel(hDC, 10, 10); // it's always white when a used is logged off

Answer 1

Try to use WTSEnumerateSessionsEx . Returned structures have helpful fields State and pUserName .