Change wallpeper in vc++ (Newbie)

I'm really new to win32 programming, and for one of my first projects I thought I would make a program to randomly changes the desktop wallpaper.

I found this function: SystemParametersInfo()
and tried to use it in a console app with MFC support like this:

int ver1;
ver1 = SystemParametersInfo(SPI_SETDESKWALLPAPER ,0,"c:/10.bmp",SPIF_SENDCHANGE);
cout << ver1 << "\n";

Strangely but not surprisingly it returned 0 and the wallpaper didn't change. I have tried including winuser.h and windows.h to no avail.
The
guide that I was following said I needed to include User32.lib so my question is:

how do I include User32.lib and if I do will my program work?

Thanks for you time

Jon

P.S I've just found another msdn guide that says exactly the sane thing apart from I need to include Coredll.lib??? any idears?

Quote:

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,"c:/10.bmp",

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try using a backslash, but im not sure if that matters.

to include the user32.lib, open your project workspace, goto project -> settings. then click on the link tab.

in the "library/object modules", add-in User32.lib, but it should already be there.

try this code:

PHP Code:

---

SystemParametersInfo(SPI_SETDESKWALLPAPER, long(0), "C:\\\\paper.bmp", SPIF_UPDATEINIFILE + SPIF_SENDWININICHANGE); 


---

you need two \\ in there so it doesnt warn you about an "unrecognized character escape sequence"

the '+' sign might not work, im not sure, but you need to include both of those vars.

hope that helps

Thanks for the help but i've tried every variation of the code you gave me but nothing seems to work.

I reckon these got to be some way of initialising the function or including a certain type of mfc support :rolleyes:

If anyone’s interested here's what I’ve done:

Started MS VC++ and made a form based project with MFC appwizard
Drew a button and added a function to it
In the function put the following code:

SystemParametersInfo(SPI_SETDESKWALLPAPER, long(0), "C:\\10.bmp", SPIF_UPDATEINIFILE + SPIF_SENDWININICHANGE);
AfxMessageBox("Function has been run");

Use the | operator to join flags:

PHP Code:

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SystemParametersInfo(SPI_SETDESKWALLPAPER, 0, "C:\\10.bmp", SPIF_UPDATEINIFILE | SPIF_SENDWININICHANGE); 


---

If it still does not work, do this directly after the funciton call:

PHP Code:

---

LPVOID lpMsgBuf;
FormatMessage(
    FORMAT_MESSAGE_ALLOCATE_BUFFER | 
    FORMAT_MESSAGE_FROM_SYSTEM |
    FORMAT_MESSAGE_IGNORE_INSERTS,
    NULL,
    GetLastError(),
    MAKELANGID(LANG_NEUTRAL, SUBLANG_DEFAULT), // Default language
    (LPTSTR) &lpMsgBuf,
    0,
    NULL );
// Process any inserts in lpMsgBuf.
// ...
// Display the string.
MessageBox( NULL, (LPCTSTR)lpMsgBuf, "Error", MB_OK |  MB_ICONINFORMATION );
// Free the buffer.
LocalFree( lpMsgBuf ); 


---

Thanks for the help guys.

GetLastError() gave me error code 120: Function not supported on this system.
So I agve it ago on my win2k box and it worked fine :D despite the help saying it supported win98.

That’s the first windows function I've ever called and M$ manage to screw it up! :mad:

Think I’ll have to get me linux :D