您不能使用 IShellFolder 进行过滤,但您可以使用 Shell 中内置的搜索工具以编程方式执行相同的操作,就像使用 Windows 资源管理器 UI 一样。
例如,您可以在右上角的搜索框中键入 ext:.txt 之类的内容,这意味着您要过滤所有带有 .txt的文件> 扩展:
这是一些等效的 C++ 示例代码(我已经删除了每一行的错误检查,但请确保您测试了所有可能的错误):
int main()
{
CoInitialize(NULL);
{
CComPtr<ISearchFolderItemFactory> search;
CComPtr<IShellItem> item;
CComPtr<IShellItemArray> items;
CComPtr<IQueryParserManager> mgr;
CComPtr<IQueryParser> parser;
CComPtr<IQuerySolution> solution;
CComPtr<ICondition> condition;
CComPtr<IShellItem> searchItem;
CComPtr<IEnumShellItems> enumItems;
// create search folder factory
search.CoCreateInstance(CLSID_SearchFolderItemFactory);
// create d:\temp shell item and set search folder scope to it
SHCreateItemFromParsingName(L"d:\\temp", NULL, IID_PPV_ARGS(&item));
SHCreateShellItemArrayFromShellItem(item, IID_PPV_ARGS(&items));
search->SetScope(items);
// create the query parser manager
mgr.CoCreateInstance(CLSID_QueryParserManager);
mgr->CreateLoadedParser(L"", 0, IID_PPV_ARGS(&parser));
// parse an ms-search expression
parser->Parse(L"ext:.txt", NULL, &solution);
// get the condition the parser has built for us
solution->GetQuery(&condition, NULL);
// give the condition to the search folder factory
search->SetCondition(condition);
// get the search result back as a shell item (a virtual folder) and enumerates it
search->GetShellItem(IID_PPV_ARGS(&searchItem));
searchItem->BindToHandler(NULL, BHID_EnumItems, IID_PPV_ARGS(&enumItems));
do
{
CComPtr<IShellItem> child;
ULONG fetched;
HRESULT hr2 = enumItems->Next(1, &child, &fetched);
if (!fetched)
break;
// get the display name (for example)
CComHeapPtr<WCHAR> name;
child->GetDisplayName(SIGDN_NORMALDISPLAY, &name);
wprintf(L"item: %s\n", name);
CComHeapPtr<WCHAR> path;
child->GetDisplayName(SIGDN_FILESYSPATH, &path);
wprintf(L" path: %s\n", path);
} while (TRUE);
}
CoUninitialize();
return 0;
}
search-ms 语言非常强大。它的语法在这里可用:Querying the Index with the search-ms Protocol