The study of Programming Windows with MFC--BitMap-优快云博客

本文链接：https://blog.youkuaiyun.com/fengshuiyue/article/details/5787586

本文介绍了使用C++和MFC进行位图创建、绘制及转换的方法，包括DDB和Bitmap的基本操作、位图到屏幕和其他设备的绘制过程、位图资源加载方式，并展示了应用程序结构示例。

摘要生成于 C知道，由 DeepSeek-R1 满血版支持，前往体验 >

1.DDB and CBitMap

CClientDC dcScreen(this);

CBitmap bitmap;

bitmap.CreateCompatibleBitMap(&dcScreen,m_nWidth,m_nHeight);

CDC dcMem;

dcMem.CreateCompatibleDC(&dcScreen);

CBitMap *pOldBitMap=dcMem.SelectObject(&bitmap);

CBrush brush(RGB(255,255,0);

dcMem.FillRect(CRect(0,0,100,100),&brush);

dcMem.SelectObject(pOldBitmap);

2.Blit Bitmap to Screen and Other Devices

void CMyBitMap::DrawBitmap(CDC *pDC, int x, int y)

{

BITMAP bm;

GetBitmap(&bm);

CSize size(bm.bmWidth, bm.bmHeight);

pDC->DPtoLP(&size);

CPoint Org(0,0);

pDC->DPtoLP(&Org);

CDC dcMem;

dcMem->CreateCompatibleDC(pDC);

CBitmap *pOldBitmap=dcMem.SelectObjec(this);

dcMem.SetMapMode(pDC->GetMapMode ());

pDC->BitBlit(x,y,size.x,size.y,pDC,Org.x,Org.y,SRCCOPY);

dcMem.SelectObject(pOldBitmap);

}

//When you pass CDC::DPtoLP the address of a CPoint object, the call goes straight through to the ::DPtoLP API function and the conversion is performed properly, even if one or more of the coordinates comes back negative. But when you pass CDC::DPtoLP the address of a CSize object, MFC performs the conversion itself and converts any negatives to positives.

3.LoadMap

//.rc

IDB_MYLOGO BITMAP Logo.bmp

CBitmap bitmap;
bitmap.LoadBitmap (IDB_MYLOGO); //bitmap.LoadMappedBitmap (IDB_BITMAP);

4.the structure of The BitmapDemo application

class CMainFrame:public CFrameWnd

{

public:

CMainFrame();

protected:

DECLARE_DYNAMIC(CMainWnd);

public:

virtual BOOL PreCreateWindow(CREATESTRUCT &cs)

virtual BOOL OnCmdMsg(UINT nID, int nCode, void* pExtra,
AFX_CMDHANDLERINFO* pHandlerInfo);

virtual ~CMainWnd();

protected:

CStatusBar m_wndStatusBar;

CChildView m_wndView;

             afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
             afx_msg void OnSetFocus(CWnd *pOldWnd);
           afx_msg BOOL OnQueryNewPalette();
             afx_msg void OnPaletteChanged(CWnd* pFocusWnd);

DECLARE_MESSAGE_MAP()
};

class CChildView : public CWnd
{

public:

CChildView();

protected:
virtual BOOL PreCreateWindow(CREATESTRUCT& cs);

              virtual ~CChildView();

    protected:
             void DoGradientFill (CDC* pDC, LPRECT pRect);
             CPalette m_palette;
             CMaskedBitmap m_bitmap;
            BOOL m_bDrawOpaque;
            afx_msg void OnPaint();
             afx_msg int OnCreate(LPCREATESTRUCT lpCreateStruct);
            afx_msg BOOL OnEraseBkgnd(CDC* pDC);
            afx_msg void OnOptionsDrawOpaque();
           afx_msg void OnOptionsDrawTransparent();
             afx_msg void OnUpdateOptionsDrawOpaque(CCmdUI* pCmdUI);
            afx_msg void OnUpdateOptionsDrawTransparent(CCmdUI* pCmdUI);
             DECLARE_MESSAGE_MAP()
    };

   class CMaskedBitmap : public CBitmap
{
   public:
            void DrawTransparent (CDC* pDC, int x, int y,COLORREF clrTransparency);
            void Draw (CDC* pDC, int x, int y);
   };