如何先后向memDC写入2张Bitmap

[code_cold]

CClientDC dc(this);
CDC memDC;
memDC.CreateCompatibleDC(&dc);
memDC.SelectObject(m_cBitmap); // The first bitmap

// Then how to read the second bitmap, When display on the screen,
// it looks like the second image on the frist image surface ?

dc.BitBlt(0, 0, width, height, &memDC, 0, 0, SRCCOPY);

[code_cold]

哈哈，没人过来

[包心菜加糯米饭]

再创建一个memdc来载入图片，然后BitBlt到这个memDC上应该可以，不过意义不大。

[code_cold]

Ok, as you said
I add the follwing

CClientDC dc(this);
CDC memDC;
memDC.CreateCompatibleDC(&dc);
CDC memDC2;
memDC2.CreateCompatibleDC(&memDC);

memDC2.SelectObject(m_cBitmap); // The first bitmap

memDC.BitBlt(0, 0, width, height, &memDC2, 0, 0, SRCCOPY);
memDC.SelectObject(m_cBitmap2);

dc.BitBlt(0, 0, width, height, &memDC, 0, 0, SRCCOPY);

But it doesn't work,
When I delete the line memDC.SelectObject(m_cBitmap2);
nothing displayed also

[包心菜加糯米饭]

你把
memDC.SelectObject(m_cBitmap2);
放到
memDC.BitBlt(0, 0, width, height, &memDC2, 0, 0, SRCCOPY);
之前，保证不要使图片覆盖，然后再试试。

[roy_hu]

attention

[code_cold]

OK, 看下面的的代码有什摸问题，Nothing displayed also

CDC memDC;
memDC.CreateCompatibleDC(&dc);
CDC tempDC;
tempDC.CreateCompatibleDC(&dc);

tempDC.SelectObject(m_cBitmap); // The first image
memDC.BitBlt(0, 0, m_nWidth - 40, m_nHeight - 90, &tempDC, 0, 0, SRCCOPY);

dc.BitBlt(20, 20, m_nWidth - 20, m_nHeight - 70, &memDC, 0, 0, SRCCOPY);

[liu_feng_fly]

你想达到什么效果？

[code_cold]

In Cleint area,
dispaly two iamges
The second (it it smaller than the other) image on the first image surface
Looks like the firs image is a backgroud,
the second iamge is the user to see object

[包心菜加糯米饭]

可能是memDC不够大，所以应该创佳一个足够大的图片来先直接创建。
我试过这样，是可以显示。
CClientDC dc(this);
CDC memDC;
CBitmap bitmap;
CBitmap bitmap1,bitmap2;
CBitmap* pBitmap1,*pBitmap2;
bitmap1.LoadBitmap(IDB_BITMAP1);
bitmap2.LoadBitmap(IDB_BITMAP2);
bitmap.CreateCompatibleBitmap(&dc,307+208,284+168);
memDC.CreateCompatibleDC(&dc);
CDC memDC2;
memDC2.CreateCompatibleDC(&memDC);

pBitmap2 = memDC2.SelectObject(&bitmap2); // The first bitmap

pBitmap1 = memDC.SelectObject(&bitmap);
memDC.BitBlt(0,0,307, 284, &memDC2, 0, 0, SRCCOPY);
memDC.BitBlt(50, 70, 307+208, 168, &memDC2, 0, 0, SRCCOPY);

dc.BitBlt(0, 0, 307+208,284+168, &memDC, 0, 0, SRCCOPY);
memDC2.SelectObject(pBitmap2);
memDC.SelectObject(pBitmap1);

[code_cold]

Very good
Very 谢谢 jiangping_zhu(娜可露露之风之刃)　

俺经常用橘佑京，鲜有对手

[包心菜加糯米饭]

我以前也是啊，不过已经不用他了。