void CsectorDlg::OnBnClickedButton1()
{
    // TODO: 在此添加控件通知处理程序代码
    UpdateData(TRUE);
    int i,j;
    unsigned char buf[512];
    OVERLAPPED overlap;
    HANDLE hFile = CreateFile(_T("\\\\.\\PhysicalDrive0"),
                       GENERIC_READ|GENERIC_WRITE,
                       FILE_SHARE_READ,
                       NULL,
                       OPEN_EXISTING,
                       NULL,//FILE_FLAG_OVERLAPPED,
                       NULL);
    DWORD RSize=0;
    overlap.Offset     = (DWORD)( m_sanqu*512ull % 0x100000000ull );
    overlap.OffsetHigh = (DWORD)( m_sanqu*512ull / 0x100000000ull );
    ReadFile(hFile, buf, 512, &RSize, &overlap/*NULL*/);
    CloseHandle(hFile);
    for(j=0;j<512;j++)
    {   
        CString buf1[1000]={0};
        if(buf[j]/16%16==0)
        {
            buf1[j].Format(_T("0%X "),buf[j]);
            if((j+1)%16==0&&(j+1))
            {
                buf1[j].Format(_T("0%X"),buf[j]);
            }
        }   
        else
        {
            buf1[j].Format(_T("%2X "),buf[j]);
            if((j+1)%16==0&&(j+1))
            {
                buf1[j].Format(_T("%2X"),buf[j]);
            }
        }
        m_sector+=buf1[j];
    }   
    UpdateData(FALSE);
}
其他地方我都做过检查了就是offset偏移那块有问题，只要有偏移在程序里就无法实现，求教一下如何实现读取位置的偏移。多谢了

fseek和ftell？

这个偏移太小了，readfile函数里自带的偏移，但我不知道哪里有错误