获得文件大小的辅助函数

//返回文件的大小的函数，如果返回true表示获取成功，i64FileSize单位为KB
bool  GetFileSize(std::wstring wstrFilePath,LONGLONG & i64FileSize)
{
DWORD   dwFileLengthLowWord= 0;
DWORD   dwFileLengthHighWord=0;

HANDLE  hFile=CreateFile(wstrFilePath.c_str(),GENERIC_READ,FILE_SHARE_READ,NULL,OPEN_EXISTING,FILE_ATTRIBUTE_READONLY,NULL);
if (hFile)
{
dwFileLengthLowWord=::GetFileSize(hFile,&dwFileLengthHighWord);

//关闭文件句柄
CloseHandle(hFile);
if ( (dwFileLengthLowWord!=INVALID_FILE_SIZE)  && (GetLastError()!=NO_ERROR))
{
MessageBox(_T("获得文件尺寸失败!"),_T("提示"),MB_OK);

return false;
}
else
{
i64FileSize= ( ((LONGLONG)dwFileLengthHighWord<<32) |(LONGLONG)dwFileLengthLowWord );

i64FileSize=i64FileSize/1024;
}
}
else
{
MessageBox(_T("打开文件失败!"),_T("提示"),MB_OK);

return false;
}

return  true;
}