改写的CBitmap类，加入了保存显示功能，新加入载入图片功能

// XMFCBMP.h: interface for the XMFCBMP class.////////////////////////////////////////////////////////////////////////#if !defined(AFX_XMFCBMP_H__329A4A70_251F_42DB_9B9A_1BB13646B3D4__INCLUDED_)#define AFX_XMFCBMP_H__329A4A70_251F_42DB_9B9A_1BB13646B3D4__INCLUDED_#if _MSC_VER > 1000#pragma once#endif // _MSC_VER > 1000class XMFCBMP : public CBitmap  {public:void createFromHBITMAP(HBITMAP *hBMP);void createFromCBitmap(CBitmap *srcBMP);XMFCBMP();virtual ~XMFCBMP();void createBMP(int nWidth, int nHeight, UINT nPlanes, UINT nBitcount, const void* lpBits );bool loadBMP(const CString strBmpPat);CDC* getMemDC(){return &dcMem;}BOOL saveBMP(char* filePath);int getHeight();int getWidth();private:CDC dcMem;CBitmap *pOldBitmap ;};#endif // !defined(AFX_XMFCBMP_H__329A4A70_251F_42DB_9B9A_1BB13646B3D4__INCLUDED_)

/********************************************************************created:2014/04/02created:2:4:2014   10:36filename: F:\Projects\DrawInMem\XMFCBMP.cppfile path:F:\Projects\DrawInMemfile base:XMFCBMPfile ext:cppauthor:XinQpurpose:*********************************************************************/// XMFCBMP.cpp: implementation of the XMFCBMP class.////////////////////////////////////////////////////////////////////////#include "stdafx.h"#include "DrawInMem.h"#include "XMFCBMP.h"#ifdef _DEBUG#undef THIS_FILEstatic char THIS_FILE[]=__FILE__;#define new DEBUG_NEW#endif//////////////////////////////////////////////////////////////////////// Construction/Destruction//////////////////////////////////////////////////////////////////////XMFCBMP::XMFCBMP(){dcMem.CreateCompatibleDC(NULL);//这里我们就在内存中虚拟建造了DC pOldBitmap = dcMem.SelectObject(this);}XMFCBMP::~XMFCBMP(){dcMem.SelectObject(pOldBitmap);dcMem.DeleteDC();//create出来的dc需要delete//get到的dc需要release}//************************************// Method:    createBMP// FullName:  XMFCBMP::createBMP// Access:    public // Returns:   void// Qualifier:// Parameter: int nWidth// Parameter: int nHeight// Parameter: UINT nPlanes// Parameter: UINT nBitcount// Parameter: const void * lpBits//************************************void XMFCBMP::createBMP(int nWidth, int nHeight, UINT nPlanes, UINT nBitcount, const void* lpBits ){DeleteObject(); CreateBitmap(nWidth, nHeight, nPlanes, nBitcount, lpBits);dcMem.SelectObject(this);}//************************************// Method:    saveBMP// FullName:  XMFCBMP::saveBMP// Access:    public // Returns:   BOOL// Qualifier:// Parameter: char * filePath//************************************BOOL  XMFCBMP::saveBMP(char* filePath)   {   HBITMAP hBitmap;// 为刚才的屏幕位图句柄HDC hDC; //设备描述表  int iBits; //当前显示分辨率下每个像素所占字节数  WORD wBitCount; //位图中每个像素所占字节数DWORD dwPaletteSize = 0, //定义调色板大小dwBmBitsSize,  //位图中像素字节大小   dwDIBSize, //位图文件大小dwWritten;  //写入文件字节数BITMAP Bitmap; //位图属性结构  BITMAPFILEHEADER bmfHdr; //位图文件头结构  BITMAPINFOHEADER bi; //位图信息头结构    LPBITMAPINFOHEADER lpbi; //指向位图信息头结构  HANDLE fh, //定义文件hDib, //分配内存句柄hPal,//调色板句柄hOldPal = NULL;//计算位图文件每个像素所占字节数  hBitmap = (HBITMAP)*this;  hDC = ::CreateDC("DISPLAY",NULL,NULL,NULL);  iBits =::GetDeviceCaps(hDC, BITSPIXEL) * ::GetDeviceCaps(hDC, PLANES);  ::DeleteDC(hDC);if (iBits <= 1)  wBitCount =1;else if(iBits <= 4)  wBitCount =4;else if (iBits <= 8)  wBitCount =8;else if(iBits <= 24)  wBitCount =24;  else if (iBits <= 32)wBitCount = 32;//计算调色板大小  if (wBitCount <= 8)  dwPaletteSize =(1 << wBitCount) * sizeof (RGBQUAD);//设置位图信息头结构  ::GetObject(hBitmap, sizeof (BITMAP), (LPSTR)&Bitmap);bi.biSize = sizeof (BITMAPINFOHEADER);  bi.biWidth = Bitmap.bmWidth;  bi.biHeight = Bitmap.bmHeight;  bi.biPlanes = 1;bi.biBitCount =wBitCount;bi.biCompression = BI_RGB;  bi.biSizeImage = 0;  bi.biXPelsPerMeter = 0;  bi.biYPelsPerMeter = 0;  bi.biClrUsed = 0;  bi.biClrImportant = 0;  dwBmBitsSize = ((Bitmap.bmWidth * wBitCount+31) / 32) * 4 * Bitmap.bmHeight;  //为位图内容分配内存  hDib = ::GlobalAlloc(GHND, dwBmBitsSize + dwPaletteSize + sizeof (BITMAPINFOHEADER));  lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDib);  *lpbi =bi;// 处理调色板    hPal = ::GetStockObject(DEFAULT_PALETTE);  if (hPal)  {  hDC = ::GetDC(NULL);hOldPal = ::SelectPalette(hDC, (HPALETTE)hPal, FALSE);RealizePalette(hDC);}  // 获取该调色板下新的像素值  GetDIBits(hDC, hBitmap,0, (UINT) Bitmap.bmHeight,(LPSTR)lpbi + sizeof (BITMAPINFOHEADER)+ dwPaletteSize,(LPBITMAPINFO)lpbi,DIB_RGB_COLORS);  //恢复调色板if (hOldPal){  SelectPalette(hDC, (HPALETTE)hOldPal, TRUE);  RealizePalette(hDC);  ::ReleaseDC(NULL, hDC);}  //创建位图文件fh = CreateFile(filePath, GENERIC_WRITE,0, NULL, CREATE_ALWAYS,FILE_ATTRIBUTE_NORMAL |FILE_FLAG_SEQUENTIAL_SCAN, NULL);  if (fh == INVALID_HANDLE_VALUE)return FALSE;  // 设置位图文件头  bmfHdr.bfType =0x4D42; // "BM"  dwDIBSize = sizeof (BITMAPFILEHEADER)  + sizeof (BITMAPINFOHEADER)  + dwPaletteSize+ dwBmBitsSize;   bmfHdr.bfSize =dwDIBSize;bmfHdr.bfReserved1 = 0;  bmfHdr.bfReserved2 = 0;  bmfHdr.bfOffBits = (DWORD)sizeof (BITMAPFILEHEADER)  + (DWORD)sizeof (BITMAPINFOHEADER)  + dwPaletteSize;// 写入位图文件头  WriteFile(fh, (LPSTR)&bmfHdr, sizeof(BITMAPFILEHEADER), &dwWritten,NULL);// 写入位图文件其余内容  WriteFile(fh, (LPSTR)lpbi, dwDIBSize,&dwWritten, NULL);//清除  GlobalUnlock(hDib);  GlobalFree(hDib);  CloseHandle(fh);  return TRUE;} //************************************// Method:    loadBMP// FullName:  XMFCBMP::loadBMP// Access:    public // Returns:   bool// Qualifier:// Parameter: const CString strBmpPath//************************************bool XMFCBMP::loadBMP(const CString strBmpPath){HBITMAP  bitmap;try{this->DeleteObject();//从文件路径加载图片bitmap =(HBITMAP)::LoadImage(NULL,strBmpPath, IMAGE_BITMAP, 0, 0,LR_CREATEDIBSECTION|LR_LOADFROMFILE|LR_DEFAULTSIZE);if(this->Attach(bitmap)){dcMem.SelectObject(this);return true;}}catch(...){return false;}return true;}int XMFCBMP::getHeight(){BITMAP bm;this->GetObject(sizeof(BITMAP),&bm);    return bm.bmHeight;}int XMFCBMP::getWidth(){BITMAP bm;this->GetObject(sizeof(BITMAP),&bm);    return bm.bmWidth;}//************************************// Method:    createFromCBitmap// FullName:  XMFCBMP::createFromCBitmap// Access:    public // Returns:   void// Qualifier:// Parameter: CBitmap * srcBMP//************************************void XMFCBMP::createFromCBitmap(CBitmap *srcBMP){BITMAP bm;srcBMP->GetBitmap(&bm);DeleteObject();CreateBitmapIndirect(&bm);//创建一样尺寸的CBitmapdcMem.SelectObject(this);//把内容拷贝进来CDC srcDC;CBitmap *pBitmap;srcDC.CreateCompatibleDC(&dcMem);pBitmap = srcDC.SelectObject(srcBMP);dcMem.BitBlt(0, 0, getWidth(), getHeight(), &srcDC, 0, 0, SRCCOPY);//删除srcdcsrcDC.SelectObject(pBitmap);DeleteDC(srcDC);}//************************************// Method:    createFromHBITMAP// FullName:  XMFCBMP::createFromHBITMAP// Access:    public // Returns:   void// Qualifier:// Parameter: HBITMAP * hBMP//************************************void XMFCBMP::createFromHBITMAP(HBITMAP *hBMP){CBitmap *pBmp = CBitmap::FromHandle(*hBMP);createFromCBitmap(pBmp);}

使用方法：

CDC *dlgDC = GetDC();//m_bmp.createBMP(200, 200, 1, 32, NULL);//创建BMP或载入bmpm_bmp.loadBMP("1.bmp");CDC *pDC = m_bmp.getMemDC();//绘图pDC->FillSolidRect(0,0,100,100,RGB(255,255,255));//这些时绘图操作，随便你^_^ char str[30];sprintf(str, "H%d*W%d", m_bmp.getHeight(), m_bmp.getWidth());pDC->TextOut(0, 0, str); pDC->Rectangle(20,20,40,40); pDC->FillSolidRect(40,40,50,50,RGB(255,0,0));//显示dlgDC->BitBlt(0,0,m_bmp.getWidth(),m_bmp.getHeight(),pDC,0,0,SRCCOPY);//第一次拷贝到屏幕 m_bmp.saveBMP("123.bmp");//保存到文件