writing Bitmap within a c++ console application

Question

i am trying to create a bitmap in mfc dll and i am writting

CDC *pDC = GetDC();
CDC memDC ;
memDC.CreateCompatibleDC(pDC);
CBitmap newbmp;
newbmp.CreateCompatibleBitmap(pDC, 300, 300);
ReleaseDC(pDC);
CBitmap *pOldBitmap = memDC.SelectObject(&newbmp); 
memDC.FillSolidRect(0,0,300,300,RGB(255,255,255));
CBrush brush;
CBrush *pOldBrush = memDC.SelectObject(&brush);
memDC.Rectangle(10, 10, 80, 80);
memDC.Ellipse(60,60,220,220);
memDC.SelectObject(pOldBrush);
memDC.SelectObject(pOldBitmap);
CImage img;
img.Attach((HBITMAP)newbmp.Detach());
img.Save(_T("C:\\atest.bmp"),Gdiplus::ImageFormatBMP);

although this works properly in a Cwindows application i cannot make it works in a console application how can i get a Device conext in a console application ? i cannot get getDC to work

Answer 1

在调用GetDC（）之前，必须具有CWnd的句柄或指针。但是在控制台应用程序中，不能调用此函数。

Answer 2

This works for me:

    CDC *pDC;
    pDC = CDC::FromHandle(::GetDC(NULL));

    CDC memDC;
    memDC.CreateCompatibleDC(pDC);

    CBitmap newbmp;
    newbmp.CreateCompatibleBitmap(pDC, 300, 300);
    CBitmap *pOldBitmap = memDC.SelectObject(&newbmp); 

    memDC.FillSolidRect(0,0,300,300,RGB(255,255,255));
    CBrush brush;
    CBrush *pOldBrush = memDC.SelectObject(&brush);
    memDC.Rectangle(10, 10, 80, 80);
    memDC.Ellipse(60,60,220,220);
    memDC.SelectObject(pOldBrush);
    memDC.SelectObject(pOldBitmap);

    CImage img;
    img.Attach((HBITMAP)newbmp.Detach());
    img.Save(_T("C:\\atest.bmp"),Gdiplus::ImageFormatBMP);

    ::ReleaseDC(    NULL,
                    *pDC);
    ::ReleaseDC(    NULL,
                    memDC);

Of course to use CDC and CBitmap you need to use MFC as a shared DLL and add some headers to the stdafx.h:

#include <afxwin.h>
#include <atlimage.h>

Hope it helps,

Javier