GDI和GDI 对象的相互转换

作者：.Live

　　当然希望可以使用GDI 来完全代替GDI，再不济也只需要从GDI对象转到GDI 对象。但是就是有那么些工程，又要新技术新特性、又希望快速开发、又不肯丢弃旧版本的已有的功能。没办法，只能缝缝补补，咔哐碙啌...
逆风编程技术

一、CDC到Graphics只要这样：

Graphics g(pDC->GetSafeHdc());//只要能构造CDC句柄的MFC对象都可以

	//CClientDC、CPaintDC，也都可以

CDC MemDC; 

CBitmap MemBitmap;

MemDC.CreateCompatibleDC(pDC);

MemBitmap.CreateCompatibleBitmap(pDC,size.cx, size.cy);

CBitmap *pOldBit=MemDC.SelectObject(&MemBitmap);

Graphics g(MemDC.GetSafeHdc());

///… you can work with GDI  … ///

Bitmap::Bitmap(HBITMAP,HPALETTE)。

static?Bitmap?*FromHBITMAP(HBITMAP?hbm,HPALETTE?hpal);

Bitmap* pPicture = new Bitmap(L"dotLive.jpg");

HBITMAP hBitmap;

CBitmap* pbm;

pPicture->GetHBITMAP(Color(0,0,0),&hBitmap);

pbm = CBitmap::FromHandle(aaa1);

///… use pbm to do the GDI works ...///

pbm->DeleteObject();//要记得删除GDI对象，否则你会发现你的内存占用…

Bitmap* tPic= new Bitmap(L"dotLive.jpg");//锁定文件

Bitmap* pPicture = new Bitmap(tPic->GetWidth()

                             ,tPic->GetHeight()

                             ,tPic->GetPixelFormat());

Graphics g(pPicture);

g.DrawImage(tPic,0,0,m_nWidth,m_nHeight);//复制过来

delete tPic;//解锁

/// … use the pPicture to access "dotLive.jpg" … ///

CLSID tiffClsid;

GetEncoderClsid(L"image/jpeg", &tiffClsid);//这个函数MSDN中有

pPicture->Save(L"dotLive.jpg" ,&tiffClsid);//保存

Bitmap* pPicture = new Bitmap(L"dotLive.jpg");//打开图片

Graphics tempG(pPicture );

HDC hdc = tempG.GetHDC ();//获得GDI句柄

CDC* tempDC = CDC::FromHandle(hdc);

/// … hurry up, draw what you want … ///

tempG.ReleaseHDC(hdc); //要记得relese，GDI都需要释放，否则资源会被占用而不接受其他操作