Win2k Desktop refuse lock

[Zhefu Zhang]

Hello, Guru, please have a look at the follwing code from "Programming Win95" . It works fine on Win95/98, but not in Win2k, please you please explain why? I have checked all handle are ok.


#include "stdafx.h"
#include <stdlib.h>

#define NUM 200

LRESULT CALLBACK WndProc (HWND, UINT, WPARAM, LPARAM) ;

int APIENTRY WinMain(HINSTANCE hInstance,
HINSTANCE hPrevInstance,
LPSTR lpCmdLine,
int nCmdShow )
{
static int iKeep [NUM][4] ;
HDC hdc, hdcMem ;
int cx, cy ;
HBITMAP hBitmap ;
int i, j, x1, y1, x2, y2 ;

if (LockWindowUpdate (GetDesktopWindow ()))
{
hdc = CreateDC ("DISPLAY", NULL, NULL, NULL) ;
hdcMem = CreateCompatibleDC (hdc) ;
cx = GetSystemMetrics (SM_CXSCREEN) / 10 ;
cy = GetSystemMetrics (SM_CYSCREEN) / 10 ;
hBitmap = CreateCompatibleBitmap (hdc, cx, cy) ;

SelectObject (hdcMem, hBitmap) ;

srand ((int) GetCurrentTime ()) ;

for (i = 0 ; i < 2 ; i++)
for (j = 0 ; j < NUM ; j++)
{
if (i == 0)
{
iKeep [j] [0] = x1 = cx * (rand () % 10) ;
iKeep [j] [1] = y1 = cy * (rand () % 10) ;
iKeep [j] [2] = x2 = cx * (rand () % 10) ;
iKeep [j] [3] = y2 = cy * (rand () % 10) ;
}
else
{
x1 = iKeep [NUM - 1 - j] [0] ;
y1 = iKeep [NUM - 1 - j] [1] ;
x2 = iKeep [NUM - 1 - j] [2] ;
y2 = iKeep [NUM - 1 - j] [3] ;
}
BitBlt (hdcMem, 0, 0, cx, cy, hdc, x1, y1, SRCCOPY) ;
BitBlt (hdc, x1, y1, cx, cy, hdc, x2, y2, SRCCOPY) ;
BitBlt (hdc, x2, y2, cx, cy, hdcMem, 0, 0, SRCCOPY) ;

Sleep (10) ;
}

DeleteDC (hdcMem) ;
DeleteDC (hdc) ;
DeleteObject (hBitmap) ;

LockWindowUpdate (NULL) ;
}

return FALSE ;
return 0;
}

[nitinsj]

Hi,
I think it happens because in Win2k the security policies are strict and if u have not logged in as adminstrator u don't have the previleges to lock the DeskTop.

enjoy,
nitin.


Rate it if it satisfies u, because that will encourage me to give more answers.
enjoy

[Zhefu Zhang]

Thanx for the reply, but I am always the admin in the local machine, the LockWindowUpdate returned TRUE(but I have to point out, it takes 5 sec in my PIII 800M machine !???). and the HDC is also valid.
?????