保存文件

CString s1;
s1.Format(L"%s",L"testpic.bmp");
GetImageBuffer(s1);
CFileDialog SaveDlg(FALSE,L"txt",L"未命名",OFN_HIDEREADONLY | OFN_OVERWRITEPROMPT,L"text文件格式(*.txt)|*.txt||",NULL);
if (SaveDlg.DoModal()==IDOK)
{
CString filename=SaveDlg.GetPathName();
CFile file(filename,CFile::modeWrite|CFile::modeCreate);
file.Write(m_pImageTempBuffer,m_nPicWidth*m_nPicHeight*4);
file.Close();
}