C / C++ / MFC

8-Oct-07 19:05

Hello Friends,

I am trying to change the Desktop Wallpaper programatically. For that I am using IActiveDesktop Interface.But not getting success, I am not getting any compile or run time error but it fails to set the wallpaper.

I am using the following code to get the path of the current Wallpaper and to set the new Wallpaper.
But I am getting only one string each time I call the GetWallpaper(), It is a follow "C:\Documents and Settings\Administrator\My Documents\My Pictures\logo.jpg"

HRESULT hr;
int Count = 0;
IActiveDesktop *pActiveDesktop;
CoInitialize(NULL);
//Create an instance of the Active Desktop
hr = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER,
            IID_IActiveDesktop, (void**)&pActiveDesktop);
WCHAR Wallpaper[MAX_PATH];
wcscpy(Wallpaper,L"c:\\a.bmp");
pActiveDesktop->SetWallpaper(Wallpaper,0);
pActiveDesktop->ApplyChanges(AD_APPLY_ALL |  AD_APPLY_FORCE);  //nothing Happens
pActiveDesktop->GetDesktopItemCount(&Count,0);  //Geting Zero everytime
pActiveDesktop->GetWallpaper(Wallpaper,MAX_PATH,0);

I also use the SystemParametersInfo API to do the same thing. But the problem is that it only wotks with .bmp file.

If you have any IDEA please tell me. Thnx in advance.

Hamid_RT8-Oct-07 19:36

Hamid_RT

8-Oct-07 19:36

Michael Dunn has an article about COMs on that article he used of this interface see this article maybe it will be helpful for you.http://www.codeproject.com/com/comintro.asp[^]

GauranG Shah8-Oct-07 20:31

8-Oct-07 20:31

I see the code it same as i am using. And problem still persist.
Is there any way I can use SystemParametersInfo API to set .jpg or .jpeg images as wallpaper or retrive the path of that.

aks.8-Oct-07 22:10

aks.

8-Oct-07 22:10

Pls have a look @ this. This work for me

#include <windows.h>
#include <wininet.h>
#include <shlobj.h>

//Main window procedure WinMain
int WINAPI WinMain (HINSTANCE hInstance, HINSTANCE hPrevInstance, LPSTR lpCmdLine, int iShowCmd)
{
CoInitialize (NULL) ;

HRESULT hr;
IActiveDesktop *pActiveDesktop;

//Create an instance of the Active Desktop
hr = CoCreateInstance(CLSID_ActiveDesktop, NULL, CLSCTX_INPROC_SERVER,
IID_IActiveDesktop, (void**)&pActiveDesktop);

//Insert code to call the IActiveDesktop methods
LPCWSTR wcPath = L"C:\\123.jpg" ;
if (pActiveDesktop -> SetWallpaper (wcPath, 0) != S_OK)
{
//The method has failed...
}

pActiveDesktop -> ApplyChanges (AD_APPLY_ALL) ;

// Call the Release method
pActiveDesktop->Release();

CoUninitialize () ;

return 0 ;
}

Ajay

GauranG Shah8-Oct-07 22:45

8-Oct-07 22:45

thnx,
When I check the error code after SetWallpaper it show '0'. that means "The operation completed successfully.". But wallpaper doesn't changed.

I am using like this.

if (pActiveDesktop -> SetWallpaper (Wallpaper, 0) != S_OK)
				{
				 dError = GetLastError(); 
                                 //Getting dError = 0   
				}

Can you tell me what can be the problem.

aks.8-Oct-07 22:47

aks.

8-Oct-07 22:47

did u call the pActiveDesktop -> ApplyChanges (AD_APPLY_ALL) ; ?

Ajay

GauranG Shah8-Oct-07 22:53

8-Oct-07 22:53

Yes using like this

pActiveDesktop->ApplyChanges(AD_APPLY_ALL |  AD_APPLY_FORCE);

But its not working. and even GetWallpaper() show me the same string as I mention above. I tried to find it on google ,but everyone uses the code like me and it works.

aks.8-Oct-07 23:05

aks.

8-Oct-07 23:05

Images that are not BMP (JPG, GIF...) will be converted to a temporary bitmap when you're selecting it from Display Properties, and this feature is functional when Active Desktop is activated.

You can find the temporary bmp file on
<windows drive="">:\Documents and Settings\<user>\Local Settings\Application Data\Microsoft\Wallpaper1.bmp

Ajay

GauranG Shah8-Oct-07 23:12

8-Oct-07 23:12

yup. I know that. but I am using .bmp file right now. And not able to set the .bmp file as the wallpaper.

If I use the Following code to set the wallpaper it works file. But it doesn't work with .jpg or .gif file.

SystemParametersInfo(SPI_SETDESKWALLPAPER,100, Wallpaper, 0);

Is there any way I can use the above code to set .gif or .jpg image as wallpaper.