Creating MFC dialog to let the user choose file path - windows

Question

As title says, I am trying to create MFC dialog-based app to let the user select the file destination folder.
I am doing this by using CMFCShellTreeCtrl. However, somehow there is only one root item which is Desktop. I would like to see all items like My Computer, C drive etc.
Could you please tell me what's wrong and how do I fix it. Thanks.
Edit: Sorry I forgot to post my code. (Very simple dialog for browsing)
// BrowseDlg.cpp : implementation file
//
#include "stdafx.h"
#include "MFC Grab to FTP.h"
#include "BrowseDlg.h"
#include "afxdialogex.h"
// CBrowseDlg dialog
IMPLEMENT_DYNAMIC(CBrowseDlg, CDialog)
CBrowseDlg::CBrowseDlg(CWnd* pParent /*=NULL*/)
: CDialog(CBrowseDlg::IDD, pParent)
{
}
CBrowseDlg::~CBrowseDlg()
{
}
void CBrowseDlg::DoDataExchange(CDataExchange* pDX)
{
CDialog::DoDataExchange(pDX);
DDX_Control(pDX, IDC_PATH, m_PathTree);
}
BEGIN_MESSAGE_MAP(CBrowseDlg, CDialog)
ON_NOTIFY(TVN_SELCHANGED, IDC_PATH, &CBrowseDlg::OnTvnSelchangedMfcshelltree1)
ON_BN_CLICKED(IDOK, &CBrowseDlg::OnBnClickedOk)
END_MESSAGE_MAP()
// CBrowseDlg message handlers
BOOL CBrowseDlg::OnInitDialog()
{
CDialog::OnInitDialog();
// Add "About..." menu item to system menu.
// IDM_ABOUTBOX must be in the system command range.
ASSERT((IDM_ABOUTBOX & 0xFFF0) == IDM_ABOUTBOX);
ASSERT(IDM_ABOUTBOX < 0xF000);
CMenu* pSysMenu = GetSystemMenu(FALSE);
if (pSysMenu != NULL)
{
BOOL bNameValid;
CString strAboutMenu;
bNameValid = strAboutMenu.LoadString(IDS_ABOUTBOX);
ASSERT(bNameValid);
if (!strAboutMenu.IsEmpty())
{
pSysMenu->AppendMenu(MF_SEPARATOR);
pSysMenu->AppendMenu(MF_STRING, IDM_ABOUTBOX, strAboutMenu);
}
}
// Set the icon for this dialog. The framework does this automatically
// when the application's main window is not a dialog
m_PathTree.Expand(m_PathTree.GetRootItem(),TVE_EXPAND);
return TRUE; // return TRUE unless you set the focus to a control
}
void CBrowseDlg::OnTvnSelchangedMfcshelltree1(NMHDR *pNMHDR, LRESULT *pResult)
{
LPNMTREEVIEW pNMTreeView = reinterpret_cast<LPNMTREEVIEW>(pNMHDR);
// TODO: Add your control notification handler code here
*pResult = 0;
}
void CBrowseDlg::OnBnClickedOk()
{
m_PathTree.GetItemPath(path,m_PathTree.GetSelectedItem());
// TODO: Add your control notification handler code here
CDialog::OnOK();
}
//
#pragma once
#include "afxshelltreectrl.h"
// CBrowseDlg dialog
// header file
class CBrowseDlg : public CDialog
{
DECLARE_DYNAMIC(CBrowseDlg)
public:
CBrowseDlg(CWnd* pParent = NULL); // standard constructor
virtual ~CBrowseDlg();
// Dialog Data
enum { IDD = IDD_BROWSER };
protected:
virtual void DoDataExchange(CDataExchange* pDX); // DDX/DDV support
DECLARE_MESSAGE_MAP()
public:
afx_msg void OnTvnSelchangedMfcshelltree1(NMHDR *pNMHDR, LRESULT *pResult);
CString path;
CMFCShellTreeCtrl m_PathTree;
afx_msg void OnBnClickedOk();
virtual BOOL OnInitDialog();
};

Answer 1

The problem is that CShellManager in not initialized. You have to do it manually. To initialize it you need to call CWinAppEx::InitShellManager() in OnInitInstance() of your CWinApp-derived class.

Answer 2

There is an alternative to using CMFCShellTreeCtrl, if you just want to pick a folder: IFileDialog.
This is my code for a select folder dialog (rather complicated, because I still want to support Windows XP using XFolderDialog):
HINSTANCE hEasyCTXP_DLL = NULL;
// Select Folder Dialog -- uses either CXFolderDialog or IFileDialog
// to open a folder picker dialog depending on OS version
// returns "" if Cancel was pressed or something else went wrong
// Note: This is just multi-byte code and not yet unicode compatible!
BOOL SelectFolder(LPSTR sFolder, LPCTSTR sTitle = "Choose Folder")
{
OSVERSIONINFOEX osvi;
ZeroMemory(&osvi, sizeof(OSVERSIONINFOEX));
osvi.dwOSVersionInfoSize = sizeof(osvi);
if (GetVersionEx((OSVERSIONINFO *)&osvi) && osvi.dwMajorVersion >= 6) // Vista or higher?
{
if (!(hEasyCTXP_DLL = LoadLibrary("XPHelper.dll")))
{
AfxMessageBox("Error opening Select Folder dialog. XPHelper.dll may not be installed properly.");
return FALSE;
}
else
{
BOOL (__cdecl *pSelectFolder)(LPSTR, LPCTSTR);
pSelectFolder = (BOOL (__cdecl *)(LPSTR, LPCTSTR))GetProcAddress(hEasyCTXP_DLL, "SelectFolder");
if (pSelectFolder)
{
return (*pSelectFolder)(sFolder, sTitle);
}
else
{
AfxMessageBox("Error opening Select Folder dialog. (SelectFolder() function entry point not found.)");
return FALSE;
}
}
}
else // XP
{
CXFolderDialog dlg(sFolder);
dlg.SetTitle(sTitle);
if (dlg.DoModal() == IDOK)
{
CString csPath = dlg.GetPath();
strcpy(sFolder, (LPCTSTR)csPath);
return TRUE;
}
else
return FALSE;
}
}
Here comes the function I provide in XPHelper.dll. This dll is delay loaded only, if Vista or later OS is used, so the main program won't fail because of missing dependencies in Windows XP:
// sFolder should be at least MAX_FILE in size!
extern "C" BOOL SelectFolder(LPSTR sFolder, LPCTSTR sTitle)
{
BOOL bRet = TRUE;
IFileDialog *pfd;
LPWSTR pwstrPath;
HRESULT hr;
if (SUCCEEDED(hr = CoCreateInstance(CLSID_FileOpenDialog, NULL, CLSCTX_INPROC_SERVER, IID_PPV_ARGS(&pfd))))
{
DWORD dwOptions;
hr = pfd->GetOptions(&dwOptions);
if (SUCCEEDED(hr))
hr = pfd->SetOptions(dwOptions | FOS_PICKFOLDERS); // put IFileDialog in folder mode
if (SUCCEEDED(hr))
{
WCHAR wcTitle[MAX_PATH+1];
if (MultiByteToWideChar(CP_ACP, 0, sTitle, (int)min(strlen(sTitle), MAX_PATH), wcTitle, sizeof(MAX_PATH + 1)))
{
wcTitle[min(strlen(sTitle), MAX_PATH)] = '\0';
pfd->SetTitle(wcTitle); // Set dialog title
}
char *cp = sFolder;
WCHAR wcDefaultPath[MAX_PATH+1];
IShellItem *psi;
if (MultiByteToWideChar(CP_ACP, 0, cp, (int)strlen(cp), wcDefaultPath, MAX_PATH + 1))
{
wcDefaultPath[strlen(cp)] = '\0';
if (SUCCEEDED(::SHCreateItemFromParsingName(wcDefaultPath, NULL, IID_PPV_ARGS(&psi))))
{
hr = pfd->SetFileName(wcDefaultPath);
hr = pfd->SetFolder(psi);
psi->Release();
}
}
}
if (SUCCEEDED(hr))
hr = pfd->Show(AfxGetMainWnd()->GetSafeHwnd());
if (SUCCEEDED(hr))
{
IShellItem *psi;
if (SUCCEEDED(pfd->GetResult(&psi)))
{
if(SUCCEEDED(psi->GetDisplayName(SIGDN_FILESYSPATH, &pwstrPath)))
{
int nSize = (int)wcslen(pwstrPath);
WideCharToMultiByte(CP_ACP, 0, pwstrPath, nSize, sFolder, MAX_PATH+1, NULL, NULL);
sFolder[nSize] = '\0';
::CoTaskMemFree(pwstrPath);
}
else
{
AfxMessageBox("IShellItem::GetDisplayName() failed.");
bRet = FALSE;
}
psi->Release();
}
else
{
AfxMessageBox("IFileDialog failed.");
bRet = FALSE;
}
}
pfd->Release();
}
if(!SUCCEEDED(hr))
bRet = FALSE;
return bRet;
}