I'm trying to count files in a desired directory using MFC...

I tried the following code:

int CountFiles(const std::string &refcstrRootDirectory,
               const std::string &refcstrExtension,
               bool              bSubdirectories = true)
  int             iCount          = 0;
  std::string     strFilePath;          // Filepath
  std::string     strPattern;           // Pattern
  //std::string     strExtension;         // Extension
  HANDLE          hFile;                // Handle to file
  WIN32_FIND_DATA FileInformation;      // File information
  std::string DoublebackSlash = "\\";

  strPattern = refcstrRootDirectory + "\\*.*";
  hFile = ::FindFirstFile(strPattern.c_str(), (&FileInformation));
      if(FileInformation.cFileName[0] != '.')
        strFilePath = refcstrRootDirectory;// + "\\" +FileInformation.cFileName;
        strFilePath += DoublebackSlash;

        CString cfilename(FileInformation.cFileName);
        CT2CA pszConvertedAnsiString(cfilename);
        std::string str (pszConvertedAnsiString);

        strFilePath += str;

        if(FileInformation.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)
            // Search subdirectory
            int iRC = CountFiles(strFilePath,
            if(iRC != -1)
              iCount += iRC;
              return -1;
          // Check extension
            CString cs(FileInformation.cFileName);

           // Convert a TCHAR string to a LPCSTR
           CT2CA pszConvertedAnsiString(cs);
           // construct a std::string using the LPCSTR input
           std::string strExtension (pszConvertedAnsiString);   //Extension

          strExtension = strExtension.substr(strExtension.rfind(".") + 1);

          if((refcstrExtension == "*") ||
             (strExtension == refcstrExtension))
            // Increase counter
    } while(::FindNextFile(hFile, &FileInformation) == TRUE);

    // Close handle

  return iCount;

but i got the following error:

hFile = ::FindFirstFile(strPattern.c_str(), (&FileInformation));

Error 4 error C2664: 'FindFirstFileW' : cannot convert parameter 1 from 'const char *' to 'LPCWSTR'

I tried to pass it in a Unicode string using _T(""), L""

hFile = ::FindFirstFile(_T(strPattern.c_str()), (&FileInformation));

but nothing happened...

here's the calling for the function:

void CSoundProjectDlg::OnBnClickedButton2()
    int iNumberOfFiles = 0;

  // Count all files in 'c:' and its subdirectories
  iNumberOfFiles = CountFiles("c:", "*");
  if(iNumberOfFiles == -1)
    // fire an error

  // Print results

  // Count '.avi' files in 'c:'
  iNumberOfFiles = CountFiles("c:", "avi", false);
  if(iNumberOfFiles == -1)
    // fire an error

  // Print results


typedef char* LPCSTR;
typedef wchar_t* LPWCSTR;

#ifndef _UNICODE

yes you correct that's the problem. that's unicode.

allright ,

I tried to pass it in a Unicode string using _T(""), L""
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hFile = ::FindFirstFile(_T(strPattern.c_str()), (&FileInformation));

hFile = ::FindFirstFile(_T(strPattern.c_str()), (&FileInformation));
but nothing happened...

First of all _T is a macro call , macros and functions are different
and sometimes they looks like similar. But it leave bugs that very
hard to debug even.

you can use _T("my string") like this
but for a variable you can't use it .

#define __T(x) L ## x

so , what it does is just only concatrate the L prefix like saying .
L"my string"

so you cannot use it for the variables.

There are other functions to convert a ASCII string to unicode , use them.

* Edit using the L prefix to the variables

Looks like the latest versions of the C++ specification allows.
However no one is going to keep all the spec in mind.
sorry about it.

however __T(x) is definied with a L if you using the unicode inside
you'r project. Try define unicode first , and if not worked then
trying the other functions.

#include "stdafx.h"

#include <iostream>
using namespace std ;

#include <string>
using std::string ;
#include <windows.h>

#define __T(x) L ## x

int main(int argc, char* argv[])
	string my_string("this is a string");

	return 0;

look at this code , and it returns the error ,
H:\STL\string\string.cpp(19) : error C2065: 'Lmy_string' : undeclared identifier

Anyway I don't know the latest versions of the C++, however

But L"my String" is correct.

well i tried to google but i didn't find any thing useful concerning converting ASCII to Unicode and vice versa using MFC...