如何在Windows 7上的C ++中为虚拟文件夹创建快捷方式？

Question

我使用的平台是Windows7。我需要在Windows 7上为虚拟文件夹创建快捷方式。我使用Windows 7 SDK示例在“计算机”下创建一个虚拟文件夹：

示例项目名称称为ExplorerDataProvider ，它为IShellFolder类定义CLSID：

// add classes supported by this module here
const CLASS_OBJECT_INIT c_rgClassObjectInit[] =
{
{ &CLSID_FolderViewImpl,            CFolderViewImplFolder_CreateInstance },
{ &CLSID_FolderViewImplContextMenu,CFolderViewImplContextMenu_CreateInstance },
};

CFolderViewImplFolder_CreateInstance的定义是：

HRESULT CFolderViewImplFolder_CreateInstance(REFIID riid, void **ppv)
{
*ppv = NULL;
CFolderViewImplFolder* pFolderViewImplShellFolder = new (std::nothrow) CFolderViewImplFolder(0);
HRESULT hr = pFolderViewImplShellFolder ? S_OK : E_OUTOFMEMORY;
if (SUCCEEDED(hr))
{
    hr = pFolderViewImplShellFolder->QueryInterface(riid, ppv);
    pFolderViewImplShellFolder->Release();
}
return hr;
}

然后CFolderViewImplFolder实现IShellFolder2和IPersistFolder2 。 我在这里找到了用于创建打印机快捷方式的类似代码： https : //www.codeproject.com/Articles/596642/Creating-a-shortcut-programmatically-in-Cplusplus和https://msdn.microsoft。 COM / EN-US /库/ aa969393.aspx＃Shellink_Item_Identifiers

一旦有了IShellFolder的类标识符，就可以调用CoCreateInstance函数来检索接口的地址。 然后，您可以调用该接口以枚举文件夹中的对象，并检索要搜索的对象的项目标识符的地址。 最后，可以在调用IShellLink :: SetIDList成员函数时使用该地址来创建该对象的快捷方式。

我修改了

hr = SHGetMalloc(&pMalloc);
hr = SHGetDesktopFolder( &pDesktopFolder );
hr = SHGetSpecialFolderLocation( NULL, CSIDL_PRINTERS, &netItemIdLst );
hr = pDesktopFolder->BindToObject( netItemIdLst, NULL, IID_IShellFolder, (void **)&pPrinterFolder );

至

// testFolder is the CLSID for the virtual folder implementation
hr = CoCreateInstance(testFolder, NULL, CLSCTX_INPROC_SERVER, IID_IShellFolder, (LPVOID*)&pVirtualFolder);

要么

hr = CoCreateInstance(testFolder, NULL, CLSCTX_INPROC_SERVER, IID_IShellFolder2, (LPVOID*)&pVirtualFolder);

但是pVirtualFolder仍然为NULL，并且打印出“找不到相应的接口”。

使用CoCreateInstance时有什么问题吗？ 还是我不应该使用这种解决方案？ 有任何示例代码吗？

Answer 1

要创建快捷方式，可以使用官方文档 。 这是为“ This PC”（又名： ComputerFolder ）的子代创建快捷方式的示例代码。

int main()
{
    CoInitialize(NULL);
    // I've used my Apple's iCloud as an example (name is in french)
    // it's a virtual folder, a shell namespace extension
    HRESULT hr = CreateComputerChildShortCut(L"Photos iCloud", L"c:\\temp\\my icloud");
    printf("hr:0x%08X\n", hr);
    CoUninitialize();
    return 0;
}

HRESULT CreateComputerChildShortCut(LPWSTR childDisplayName, LPWSTR path)
{
    // get My Computer folder's ShellItem (there are other ways for this...)
    CComPtr<IShellItem> folder;
    HRESULT hr = SHCreateItemInKnownFolder(FOLDERID_ComputerFolder, 0, NULL, IID_PPV_ARGS(&folder));
    if (FAILED(hr)) return hr;

    // enumerate children
    CComPtr<IEnumShellItems> items;
    hr = folder->BindToHandler(NULL, BHID_EnumItems, IID_PPV_ARGS(&items));
    if (FAILED(hr)) return hr;

    for (CComPtr<IShellItem> item; items->Next(1, &item, NULL) == S_OK; item.Release())
    {
        // get parsing path (if's often useful)
        CComHeapPtr<wchar_t> parsingPath;
        item->GetDisplayName(SIGDN_DESKTOPABSOLUTEPARSING, &parsingPath);
        wprintf(L"Path: %s\n", parsingPath);

        // get display name
        CComHeapPtr<wchar_t> displayName;
        item->GetDisplayName(SIGDN_NORMALDISPLAY, &displayName);
        wprintf(L" Name: %s\n", displayName);

        if (!lstrcmpi(childDisplayName, displayName))
        {
            // get pidl
            // it's the unambiguous way of referencing a shell thing
            CComHeapPtr<ITEMIDLIST> pidl;
            hr = SHGetIDListFromObject(item, &pidl);
            if (FAILED(hr)) return hr;

            // create an instance of the standard Shell's folder shortcut creator
            CComPtr<IShellLink> link;
            hr = link.CoCreateInstance(CLSID_FolderShortcut);
            if (FAILED(hr)) return hr;

            // just use the pidl
            hr = link->SetIDList(pidl);
            if (FAILED(hr)) return hr;

            CComPtr<IPersistFile> file;
            hr = link->QueryInterface(&file);
            if (FAILED(hr)) return hr;

            // save the shortcut (we could also change other IShellLink parameters)
            hr = file->Save(path, FALSE);
            if (FAILED(hr)) return hr;
            break;
        }
    }
    return S_OK;
}

当然，如果您知道绝对的解析路径或绝对的pidl，则不必枚举任何内容，这只是出于演示目的。