I'm writing a MFC program that can occasionally remove a directory with all of its content. These directories will be located in %LOCALAPPDATA%\MyApp so there will be no permission issue (at least I hope).
My first guess was to use CFileFind recursively along with DeleteFile and DeleteDirectory Win32 functions, but a fast look at RemoveDirectory documentation pointed me to SHFileOperation and finally to IFileOperation which, if I have understood, should be the way how a pure Windows Desktop Application has to interact with the file system, so I would exclude the std::filesystem::remove_all solution if possible.
Now, this is surely a problem of mine because I hate COM, but I found this documentation not very clear if not cryptic, so I decided to have a look at the developer's guide where I got to the File Operations Samples which surely helps to understand, but not completely because in my case I have to find the files to delete, so I finally got to this guide which should contains all the informations I'm looking for.
Now, if I got the situation I have to:
In plain ol' C++:
void CWindowsUtilities::RemoveDirectory(HWND parent, CString& directory)
{
IShellFolder* desktop;
HRESULT res = SHGetDesktopFolder(&desktop);
if (SUCCEEDED(res))
{
ULONG eaten = 0UL;
LPITEMIDLIST itemIdList;
res = desktop->ParseDisplayName(parent, nullptr, directory.GetBuffer(), &eaten, &itemIdList, nullptr);
if (SUCCEEDED(res))
{
IShellFolder* directoryToDelete;
res = desktop->BindToObject(itemIdList, nullptr, IID_IShellFolder, reinterpret_cast<LPVOID*>(&directoryToDelete));
if (SUCCEEDED(res))
{
IEnumIDList* elementsToDelete;
res = directoryToDelete->EnumObjects(parent, SHCONTF_INCLUDEHIDDEN | SHCONTF_CHECKING_FOR_CHILDREN | SHCONTF_FOLDERS | SHCONTF_NAVIGATION_ENUM, &elementsToDelete);
if (res == S_OK)
{
IFileOperation* fileOp;
res = CoCreateInstance(__uuidof(FileOperation), nullptr, CLSCTX_ALL, IID_PPV_ARGS(&fileOp));
if (SUCCEEDED(res))
{
res = fileOp->SetOperationFlags(FOFX_ADDUNDORECORD | FOFX_RECYCLEONDELETE);
if (SUCCEEDED(res))
{
res = fileOp->QueryInterface(IID_PPV_ARGS(&fileOp));
if (SUCCEEDED(res))
{
res = fileOp->DeleteItems(elementsToDelete);
if (SUCCEEDED(res))
{
res = fileOp->PerformOperations();
}
}
}
}
fileOp->Release();
}
directoryToDelete->Release();
}
CoTaskMemFree(itemIdList);
}
desktop->Release();
}
}
Letting run the code it goes without exceptions, but on DeleteItems I got:
E_NOINTERFACE No such interface supported.
Trying to understand where my problem can be, I've tried to enumerate the files in the directory using:
void CWindowsUtilities::Navigate(IShellFolder* accesso)
{
IEnumIDListPtr file;
HRESULT res = accesso->EnumObjects(nullptr, SHCONTF_FOLDERS, &file);
if (res == S_OK)
{
LPITEMIDLIST itemID;
ULONG fetched;
while (file->Next(1UL, &itemID, &fetched) == S_OK)
{
STRRET nome = { 0 };
accesso->GetDisplayNameOf(itemID, SHGDN_NORMAL, &nome);
CoTaskMemFree(itemID);
}
file->Release();
}
}
and so I can see that I can navigate the desktop but not the directory I want to delete. I also tried using SHParseDisplayName instead of desktop->ParseDisplayName but with no success, even if I got a different itemIdList.
What am I doing wrong?
You can use SHFileOperation It has been replaced in Windows vista but still works great.
SHFILEOPSTRUCT SHFileOp, SHDirOp;
ZeroMemory(&SHDirOp, sizeof(SHFILEOPSTRUCT));
SHDirOp.hwnd = NULL;
SHDirOp.wFunc = FO_DELETE;
SHDirOp.pFrom = _T("path to folder");
SHDirOp.pTo = NULL;
SHDirOp.fFlags =
FOF_MULTIDESTFILES /* | FOF_NOCONFIRMMKDIR | FOF_NOCONFIRMATION */;
//The Copying Function
SHFileOperation(&SHDirOp);
If you really want to use the IFileOperator here is how you could use it:
BOOL deleteFileOrFolder(LPCWSTR fileOrFolderPath) {
HRESULT hr = CoInitializeEx(NULL, COINIT_MULTITHREADED);
if (FAILED(hr)) {
//Couldn't initialize COM library - clean up and return
MessageBox(NULL, L"Couldn't initialize COM library", L"Whoops", MB_OK | MB_ICONERROR);
CoUninitialize();
return FALSE;
}
//Initialize the file operation
IFileOperation* fileOperation;
hr = CoCreateInstance(CLSID_FileOperation, NULL, CLSCTX_ALL, IID_PPV_ARGS(&fileOperation));
if (FAILED(hr)) {
//Couldn't CoCreateInstance - clean up and return
MessageBox(NULL, L"Couldn't CoCreateInstance", L"Whoops", MB_OK | MB_ICONERROR);
CoUninitialize();
return FALSE;
}
hr = fileOperation->SetOperationFlags(FOF_NOCONFIRMATION | FOF_SILENT | FOF_NOERRORUI);
if (FAILED(hr)) {
//Couldn't add flags - clean up and return
MessageBox(NULL, L"Couldn't add flags", L"Whoops", MB_OK | MB_ICONERROR);
fileOperation->Release();
CoUninitialize();
return FALSE;
}
IShellItem* fileOrFolderItem = NULL;
hr = SHCreateItemFromParsingName(fileOrFolderPath, NULL, IID_PPV_ARGS(&fileOrFolderItem));
if (FAILED(hr)) {
//Couldn't get file into an item - clean up and return (maybe the file doesn't exist?)
MessageBox(NULL, L"Couldn't get file into an item", L"Whoops", MB_OK | MB_ICONERROR);
fileOrFolderItem->Release();
fileOperation->Release();
CoUninitialize();
return FALSE;
}
hr = fileOperation->DeleteItem(fileOrFolderItem, NULL); //The second parameter is if you want to keep track of progress
fileOrFolderItem->Release();
if (FAILED(hr)) {
//Failed to mark file/folder item for deletion - clean up and return
MessageBox(NULL, L"Failed to mark file/folder item for deletion", L"Whoops", MB_OK | MB_ICONERROR);
fileOperation->Release();
CoUninitialize();
return FALSE;
}
hr = fileOperation->PerformOperations();
fileOperation->Release();
CoUninitialize();
if (FAILED(hr)) {
//failed to carry out delete - return
MessageBox(NULL, L"failed to carry out delete", L"Whoops", MB_OK | MB_ICONERROR);
return FALSE;
}
return TRUE;
}
Both methods had already been resolved in SO in the following links respectively:
https://stackoverflow.com/a/22226730/1856251
https://stackoverflow.com/a/68736092/1856251
Looking at your code I can see that one of the things you are doing wrong is that as per IFileOperation::DeleteItems documentation it takes a pointer of one of the following: IShellItemArray, IDataObject, IEnumShellItems or IPersistIDList. But you are passing a IEnumIDList pointer.