MFC制作简易地图导航遇到打开保存数据问题

正在做一个简易地图导航，在道路上可以添加节点，道路和节点保存在一起，怎么编写打开和保存的BUTTON的代码
CStdioFile file;
    file.Open("F:\\data.txt",CFile::modeWrite|CFile::modeNoTruncate|CFile::modeCreate);
    CString data;
    char b[10];
    itoa(m_dllb.GetCount(),b,10);
    file.WriteString(b);
    file.WriteString("\n");
    for(roadid=0;roadid<m_dllb.GetCount();roadid++){
        itoa(Road[roadid].id,b,10);
        file.WriteString(b);
        file.WriteString("\n");
        file.WriteString(Road[roadid].roadname);
        file.WriteString("\n");
        /*for(nodeid=0;nodeid<Road[roadid].nodes.size();nodeid++){
            char b[10],c[10];
            itoa(Road[roadid].nodes[nodeid].x,b,10);
            itoa(Road[roadid].nodes[nodeid].y,c,10);
            CString temp;
            //temp=Road[roadid].nodes[nodeid].name;
            temp+=b;
            temp+=",";
            temp+=c;
            m_points.AddString(temp);
            //MessageBox("刷新节点","提示",MB_OK);
        }*/
    }
    file.Close();这个保存的代码节点存不进去为什么