如何获得打印机图标

Question

sorry this may look like a duplicate question because a similar question was posted but the answers which were given weren't complete. i want to create a list of available printers stating the status of the printer and the icon associated with each printer. at this point am able to get the list and their associated states, but where am failing is getting the icons. from the earlier posted question the answer involved using SHGetFileInfo, but when i tried it no icons were returned. i suspect there was something i need to do before calling SHGetFileInfo because the answer included a statement which involved combining two PIDLs, now because it wasn't actual code but a comment i couldn't fully understand how to implement it. here is a link to the question

for (int i=0; i < dwReturned; i++)
{
    HICON hIcon = NULL;

    LPITEMIDLIST pidlPrinters = NULL;
    LPITEMIDLIST pidl = NULL;
    LPENUMIDLIST pEnum = NULL;
    LPSHELLFOLDER pDesktopFolder = NULL;
    IShellFolder* psfPrinters = NULL;
    STRRET strName;
    TCHAR pszDisplayName[MAX_PATH];
    HRESULT hr;
    SHFILEINFO sfi;

    hr = SHGetFolderLocation(m_pParentWnd->m_hWnd, CSIDL_PRINTERS, 0, 0, &pidlPrinters);

    if(hr == S_OK)
    {
        hr = SHGetDesktopFolder(&pDesktopFolder);
    }

    if(hr == S_OK)
    {
        hr = pDesktopFolder->BindToObject(pidlPrinters, 0, IID_IShellFolder, reinterpret_cast<void**> 
             (&psfPrinters));
    }

    if(hr == S_OK)
    {
        hr = psfPrinters->EnumObjects(m_pParentWnd->m_hWnd, SHCONTF_FOLDERS | SHCONTF_NONFOLDERS, 
            &pEnum);
    }

    if(hr == S_OK)
    {
        while (pEnum->Next(1, &pidl, 0) == S_OK)
        {
            psfPrinters->GetDisplayNameOf(pidl,SHGDN_NORMAL, &strName);

            StrRetToBuf(&strName, pidl, pszDisplayName, MAX_PATH);

            //pInfo is PRINTER_INFO_2 *

            if (_wcsicmp(pszDisplayName, pInfo[i].pPrinterName) == 0)
            {
                SHGetFileInfo((LPCTSTR)pidl, 0, &sfi, sizeof(SHFILEINFO),  SHGFI_PIDL | SHGFI_ICON | 
                SHGFI_DISPLAYNAME | SHGFI_TYPENAME); 
                hIcon = sfi.hIcon;
            }

            IMalloc* Malloc = NULL;
            SHGetMalloc(&Malloc);
            Malloc->Free(pidl);
            Malloc->Release();
       }

       pDesktopFolder->Release();
       pEnum->Release();

       //Some other code
    }
}

Answer 1

You can use IShellFolder::GetUIObjectOf to extract the icon, the following is an example you can have a try.

            psfPrinters->GetDisplayNameOf(pidl, SHGDN_NORMAL, &strName);

            IExtractIcon* eIcon = NULL;
            hr = psfPrinters->GetUIObjectOf(NULL, 1, (LPCITEMIDLIST*)&pidl, IID_IExtractIcon, NULL, reinterpret_cast<void**>(&eIcon));
            if (hr == S_OK)
            {
                WCHAR iconFileLocation[200];
                int index;
                UINT flag = 0;
                hr = eIcon->GetIconLocation(NULL, iconFileLocation, sizeof(iconFileLocation), &index, &flag);
                if (hr == S_OK)
                {
                    UINT size = 100;
                    eIcon->Extract(iconFileLocation, index, &hIcon, NULL, size);
                    if (hr == S_OK)
                    {
                        // Draw printer icon on client area for checking purpose
                        DrawIcon(hdc, xNew, y, hIcon);
                        xNew += size;
                    }
                }
            }

Sample output of above code: