遍历读取指定文件夹下指定类型的所有文件

经常碰到朋友，尤其是初学者对指定文件夹下指定类型文件的读取很困惑，这里，我把自己经常用的程序贴出来，供初学者学些；

#include "stdafx.h"
#include "windows.h"
#include <vector>
#include <string>
#include "iostream"
using namespace std;
typedef std::vector<std::string> file_lists;

static int str_compare(const void *arg1, const void *arg2)
{
return strcmp((*(std::string*)arg1).c_str(), (*(std::string*)arg2).c_str());//比较字符串arg1 and arg2
}

file_lists ScanDirectory(const std::string &path, const std::string &extension)
{
WIN32_FIND_DATA wfd;//WIN32_FIND_DATA:Contains information about the file that is found by the
//FindFirstFile, FindFirstFileEx, or FindNextFile function
HANDLE hHandle;
string searchPath, searchFile;
file_lists vFilenames;
int nbFiles = 0;

searchPath = path + "/*" + extension;
hHandle = FindFirstFile(searchPath.c_str(), &wfd);//Searches a directory for a file or subdirectory
//with a name that matches a specific name
if (INVALID_HANDLE_VALUE == hHandle)
{
fprintf(stderr, "ERROR(%s, %d): Cannot find (*.%s)files in directory %s/n",
__FILE__, __LINE__, extension.c_str(), path.c_str());
exit(0);
}
do
{
//. or ..
if (wfd.cFileName[0] == '.')
{
continue;
}
// if exists sub-directory
if (wfd.dwFileAttributes & FILE_ATTRIBUTE_DIRECTORY)//dwFileAttributes:The file attributes of a file
{

//FILE_ATTRIBUTE_DIRECTORY:The handle identifies a directory
continue;
}
else//if file
{
searchFile = path + "/" + wfd.cFileName;
vFilenames.push_back(searchFile);
nbFiles++;
}
}while (FindNextFile(hHandle, &wfd));//Call this member function to continue a file search begun
//with a call to CGopherFileFind::FindFile

FindClose(hHandle);//Closes a file search handle opened by the FindFirstFile, FindFirstFileEx,
//or FindFirstStreamW function

// sort the filenames
qsort((void *)&(vFilenames[0]), (size_t)nbFiles, sizeof(string), str_compare);//Performs a quick sort

return vFilenames;
}

int _tmain(int argc, _TCHAR* argv[])
{
file_lists files = ScanDirectory("D://PicturesForTestInTheHall//TestGroup5", ".jpg");
if (files.empty())
{
cout<<"no image file find in current directory.."<<endl;
system("pause");
exit(-1);
}

int size = files.size();
cout<<"there are "<<size<<" image files totally...."<<endl;
for (int i=0; i<size; i++)
{
cout<<files[i].c_str()<<endl;
}

system("pause");
return 0;
}