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;
}