问题
By using Microsoft windows SDK 7.0, explorerDataProvider, I installed a virtual folder on windows 7.
When I open the file browse dialog from an application,
CFileDialog dlg(TRUE, NULL, 0, OFN_ENABLESIZING | OFN_ALLOWMULTISELECT, L"all(*.*)|*.*||", this);
INT_PTR result = dlg.DoModal();
if (result == IDOK)
{
.
.
.
//some actions
}
it can also display the virtual folder:
But when I select the file, like "Zero" can then clicks "Open",
I tried to add breakpoints to
INT_PTR result = dlg.DoModal();
But it seems that this error happens inside DoModal().
I doing some research and revise the code of virtual folder:
HRESULT CFolderViewImplFolder::GetAttributesOf(UINT cidl, PCUITEMID_CHILD_ARRAY apidl, ULONG *rgfInOut)
{
// If SFGAO_FILESYSTEM is returned, GetDisplayNameOf(SHGDN_FORPARSING) on that item MUST
// return a filesystem path.
HRESULT hr = E_INVALIDARG;
DWORD dwAttribs = 0;
dwAttribs |= SFGAO_BROWSABLE;
if (1 == cidl)
{
int nLevel = 0;
hr = _GetLevel(apidl[0], &nLevel);
if (SUCCEEDED(hr))
{
BOOL fIsFolder = FALSE;
hr = _GetFolderness(apidl[0], &fIsFolder);
if (SUCCEEDED(hr))
{
if (fIsFolder)
{
dwAttribs |= SFGAO_FOLDER;
dwAttribs |= SFGAO_FILESYSANCESTOR;
}
else
{
dwAttribs |= SFGAO_SYSTEM;
dwAttribs |= SFGAO_FILESYSTEM;
}
if (nLevel < g_nMaxLevel)
{
dwAttribs |= SFGAO_HASSUBFOLDER;
}
}
}
}
*rgfInOut &= dwAttribs;
return hr;
}
And return the path inGetDisplayNameOf()
HRESULT CFolderViewImplFolder::GetDisplayNameOf(PCUITEMID_CHILD pidl, SHGDNF shgdnFlags, STRRET *pName)
{
HRESULT hr = S_OK;
if (shgdnFlags & SHGDN_FORPARSING)
{
WCHAR szDisplayName[MAX_PATH];
if (shgdnFlags & SHGDN_INFOLDER)
{
// This form of the display name needs to be handled by ParseDisplayName.
hr = _GetName(pidl, szDisplayName, ARRAYSIZE(szDisplayName));
}
else
{
PWSTR pszThisFolder = L"Computer\\Jerry";
StringCchCopy(szDisplayName, ARRAYSIZE(szDisplayName), pszThisFolder);
StringCchCat(szDisplayName, ARRAYSIZE(szDisplayName), L"\\");
WCHAR szName[MAX_PATH];
hr = _GetName(pidl, szName, ARRAYSIZE(szName));
if (SUCCEEDED(hr))
{
StringCchCat(szDisplayName, ARRAYSIZE(szDisplayName), szName);
}
}
if (SUCCEEDED(hr))
{
hr = StringToStrRet(szDisplayName, pName);
}
}
else
{
PWSTR pszName;
hr = _GetName(pidl, &pszName);
if (SUCCEEDED(hr))
{
hr = StringToStrRet(pszName, pName);
CoTaskMemFree(pszName);
}
}
return hr;
}
But it still stats error message of "Path does not exist" in the application.
I add breakpoints in GetDisplayNameOf, but it is never triggered when the application opens a file browse dialog. But if I open a regular folder just by double click "Computer", it will be triggered.
The error message of "Path does not exist" seems cannot be deprecated or covered. Any way that I can revise the virtual folder to return the correct path ?
Update: I tried IFileDialog, I copied the code from the MSDN sample, code, and add breakpoints to see what will happen. However,
// Show the dialog
hr = pfd->Show(NULL);//the breakpoint is added here
if (SUCCEEDED(hr))
{
// Obtain the result once the user clicks
// the 'Open' button.
// The result is an IShellItem object.
IShellItem *psiResult;
hr = pfd->GetResult(&psiResult);
if (SUCCEEDED(hr))
{
//do something
}
}
When I click "Open" button, the error message box of "Path does not exist, check the path and try again" still show up. And it never comes out of pfd->Show(NULL) after I click Open" button.
Based on the comments in the sample code, it should come out of hr = pfd->Show(NULL); and reach to the next line.but the error message happens inside the hr = pfd->Show(NULL);.
Update:
In the IFileDialog, I tried
hr = pfd->GetOptions(&dwFlags);
if (SUCCEEDED(hr))
{
hr = pfd->SetOptions(dwFlags | FOS_ALLNONSTORAGEITEMS);
if (SUCCEEDED(hr))
{
// Show the dialog
hr = pfd->Show(NULL);
if (SUCCEEDED(hr))
{
// Obtain the result once the user clicks
// the 'Open' button.
// The result is an IShellItem object.
IShellItem *psiResult;
hr = pfd->GetResult(&psiResult);
if (SUCCEEDED(hr))
{
// We are just going to print out the
// name of the file for sample sake.
PWSTR pszFilePath = NULL;
hr = psiResult->GetDisplayName(SIGDN_FILESYSPATH,
&pszFilePath);
if (SUCCEEDED(hr))
{
TaskDialog(NULL,
NULL,
L"CommonFileDialogApp",
pszFilePath,
NULL,
TDCBF_OK_BUTTON,
TD_INFORMATION_ICON,
NULL);
CoTaskMemFree(pszFilePath);
}
psiResult->Release();
}
}
}
I also tried
hr = pfd->SetOptions(dwFlags);//delete FOS_FORCEFILESYSTEM
And tried
DWORD dwFlags = 0;
if (SUCCEEDED(hr))
{
// overwrite options completely
hr = pfd->SetOptions(dwFlags | FOS_ALLNONSTORAGEITEMS);
I also tried to return the whole name in namespace extension code:
WCHAR szDisplayName[MAX_PATH];
if (shgdnFlags & SHGDN_INFOLDER)
{
// This form of the display name needs to be handled by ParseDisplayName.
hr = _GetName(pidl, szDisplayName, ARRAYSIZE(szDisplayName));
}
else
{
PWSTR pszThisFolder;// = L"Computer\\Jerry";
hr = SHGetNameFromIDList(m_pidl, (shgdnFlags & SHGDN_FORADDRESSBAR) ? SIGDN_DESKTOPABSOLUTEEDITING : SIGDN_DESKTOPABSOLUTEPARSING, &pszThisFolder);
if (SUCCEEDED(hr))
{
StringCchCopy(szDisplayName, ARRAYSIZE(szDisplayName), pszThisFolder);
StringCchCat(szDisplayName, ARRAYSIZE(szDisplayName), L"\\");
WCHAR szName[MAX_PATH];
hr = _GetName(pidl, szName, ARRAYSIZE(szName));
if (SUCCEEDED(hr))
{
StringCchCat(szDisplayName, ARRAYSIZE(szDisplayName), szName);
}
CoTaskMemFree(pszThisFolder);
}
}
if (SUCCEEDED(hr))
{
hr = StringToStrRet(szDisplayName, pName);
}
But the result is:
Update:
hr = pfd->SetOptions(dwFlags | FOS_ALLNONSTORAGEITEMS | FOS_NOVALIDATE);
This works for me!!
回答1:
With the help of @RemyLebeau, I did some tests in my code. Finally, I found the working solution for me:
I copied the code from MSDN for IFileDialog: https://msdn.microsoft.com/en-us/library/windows/desktop/bb776913.aspx#file_types
and then revise it a little bit:
HRESULT BasicFileOpen()
{
// CoCreate the File Open Dialog object.
IFileDialog *pfd = NULL;
HRESULT hr = CoCreateInstance(CLSID_FileOpenDialog,
NULL,
CLSCTX_INPROC_SERVER,
IID_PPV_ARGS(&pfd));
if (SUCCEEDED(hr))
{
// Create an event handling object, and hook it up to the dialog.
IFileDialogEvents *pfde = NULL;
hr = CDialogEventHandler_CreateInstance(IID_PPV_ARGS(&pfde));
if (SUCCEEDED(hr))
{
// Hook up the event handler.
DWORD dwCookie;
hr = pfd->Advise(pfde, &dwCookie);
if (SUCCEEDED(hr))
{
// Set the options on the dialog.
DWORD dwFlags = 0;
if (SUCCEEDED(hr))
{
// the default flag is FOS_PATHMUSTEXIST and FOS_FILEMUSTEXIST, so I set overwrite it with these two flags.
hr = pfd->SetOptions(dwFlags | FOS_ALLNONSTORAGEITEMS | FOS_NOVALIDATE);
if (SUCCEEDED(hr))
{
// Show the dialog
hr = pfd->Show(NULL);
if (SUCCEEDED(hr))
{
// Obtain the result once the user clicks
// the 'Open' button.
// The result is an IShellItem object.
IShellItem *psiResult;
hr = pfd->GetResult(&psiResult);
if (SUCCEEDED(hr))
{
// We are just going to print out the
// name of the file for sample sake.
PWSTR pszFilePath = NULL;
hr = psiResult->GetDisplayName(SIGDN_FILESYSPATH,
&pszFilePath);
if (SUCCEEDED(hr))
{
TaskDialog(NULL,
NULL,
L"CommonFileDialogApp",
pszFilePath,
NULL,
TDCBF_OK_BUTTON,
TD_INFORMATION_ICON,
NULL);
CoTaskMemFree(pszFilePath);
}
psiResult->Release();
}
}
}
}
// Unhook the event handler.
pfd->Unadvise(dwCookie);
}
pfde->Release();
}
pfd->Release();
}
return hr;
}
The key point is to overwrite the options by SetOptions. Based on the MSDN:https://msdn.microsoft.com/en-us/library/windows/desktop/dn457282(v=vs.85).aspx ,
FOS_PATHMUSTEXIST
The item returned must be in an existing folder. This is a default value.
FOS_FILEMUSTEXIST
The item returned must exist. This is a default value for the Open dialog.
These flags are default values which prevent it returns. So I set it to :
hr = pfd->SetOptions(dwFlags | FOS_ALLNONSTORAGEITEMS | FOS_NOVALIDATE);
These flags mean:
FOS_NOVALIDATE
Do not check for situations that would prevent an application from opening the selected file, such as sharing violations or access denied errors.
and
FOS_ALLNONSTORAGEITEMS
Enables the user to choose any item in the Shell namespace, not just those with SFGAO_STREAM or SFAGO_FILESYSTEM attributes. This flag cannot be combined with FOS_FORCEFILESYSTEM.
Then it finally works!
来源：https://stackoverflow.com/questions/47168882/cannot-get-the-path-for-the-virtual-folder-on-windows-7-cshell-namespace-exte