我把一幅图片选入到了内存DC中同时也进行了画了一条线的操作
CDC *pDC = GetDC();
m_dccompatible.CreateCompatibleDC(pDC);
m_dccompatible.m_hDC = m_ImageProcess.LoadImage(pDC->m_hDC, strPath, m_Rect, fSize);
ReleaseDC(pDC); m_dccompatible.MoveTo(20, 20);
m_dccompatible.LineTo(300, 300);在OnPaint中也把内存DC中内容拷贝到了目标DC中显示出来，也确实能在图片上显示出一条线了。
BitBlt(dc.m_hDC, x, y/*m_Rect.left, m_Rect.top*/, m_Rect.right, m_Rect.bottom,m_dccompatible.m_hDC, m_nXScrollPos, m_nYScrollPos, SRCCOPY);但是现在如何把内存DC m_dccompatible中的图像保存到strPath的图片本身呢？
CDC *pDC = GetDC();
m_dccompatible.CreateCompatibleDC(pDC);
m_dccompatible.m_hDC = m_ImageProcess.LoadImage(pDC->m_hDC, strPath, m_Rect, fSize);
ReleaseDC(pDC); m_dccompatible.MoveTo(20, 20);
m_dccompatible.LineTo(300, 300);在OnPaint中也把内存DC中内容拷贝到了目标DC中显示出来，也确实能在图片上显示出一条线了。
BitBlt(dc.m_hDC, x, y/*m_Rect.left, m_Rect.top*/, m_Rect.right, m_Rect.bottom,m_dccompatible.m_hDC, m_nXScrollPos, m_nYScrollPos, SRCCOPY);但是现在如何把内存DC m_dccompatible中的图像保存到strPath的图片本身呢？
//////////////////////////////////////////////////////////////////
// Save Bitmap To File
//////////////////////////////////////////////////////////////////
BOOL SaveBtimapToFile(HBITMAP hBmp,LPCTSTR pszFileName)
{
HDC hDC;
//当前分辨率下每象素所占字节数
int iBits;
//位图中每象素所占字节数
WORD wBitCount;
//定义调色板大小， 位图中像素字节大小 ，位图文件大小 ， 写入文件字节数
DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0;
//位图属性结构
BITMAP Bitmap;
//位图文件头结构
BITMAPFILEHEADER bmfHdr;
//位图信息头结构
BITMAPINFOHEADER bi;
//指向位图信息头结构
LPBITMAPINFOHEADER lpbi;
//定义文件，分配内存句柄，调色板句柄
HANDLE fh, hDib, hPal,hOldPal=NULL; //计算位图文件每个像素所占字节数
hDC = CreateDC(L"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
wBitCount = 24; GetObject(hBmp, 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.biClrImportant = 0;
bi.biClrUsed = 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,hBmp, 0,(UINT)Bitmap.bmHeight,
(LPSTR)lpbi+ sizeof(BITMAPINFOHEADER)+dwPaletteSize,
(BITMAPINFO *)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(pszFileName, 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;
}
BOOL SaveBmp(HBITMAP hBitmap, CString FileName)
{
HDC hDC;
//当前分辨率下每象素所占字节数
int iBits;
//位图中每象素所占字节数
WORD wBitCount;
//定义调色板大小， 位图中像素字节大小 ，位图文件大小 ， 写入文件字节数
DWORD dwPaletteSize=0, dwBmBitsSize=0, dwDIBSize=0, dwWritten=0;
//位图属性结构
BITMAP Bitmap;
//位图文件头结构
BITMAPFILEHEADER bmfHdr;
//位图信息头结构
BITMAPINFOHEADER bi;
//指向位图信息头结构
LPBITMAPINFOHEADER lpbi;
//定义文件，分配内存句柄，调色板句柄
HANDLE fh, hDib, hPal,hOldPal=NULL; //计算位图文件每个像素所占字节数
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 wBitCount = 24; 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.biClrImportant = 0;
bi.biClrUsed = 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);
//hDC = m_pDc-> GetSafeHdc();
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, (BITMAPINFO *)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(FileName, 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;
}
HBITMAP CopyDCToBitmap(HDC hScrDC, LPRECT lpRect)
{
HDC hMemDC;
// 屏幕和内存设备描述表
HBITMAP hBitmap,hOldBitmap;
// 位图句柄
int nX, nY, nX2, nY2;
// 选定区域坐标
int nWidth, nHeight;
// 位图宽度和高度 // 确保选定区域不为空矩形
if (IsRectEmpty(lpRect))
return NULL; // 获得选定区域坐标
nX = lpRect-> left;
nY = lpRect-> top;
nX2 = lpRect-> right;
nY2 = lpRect-> bottom;
nWidth = nX2 - nX;
nHeight = nY2 - nY;
//为屏幕设备描述表创建兼容的内存设备描述表
hMemDC = CreateCompatibleDC(hScrDC);
// 创建一个与屏幕设备描述表兼容的位图
hBitmap = CreateCompatibleBitmap(hScrDC, nWidth, nHeight);
// 把新位图选到内存设备描述表中
hOldBitmap = (HBITMAP)SelectObject(hMemDC, hBitmap);
// 把屏幕设备描述表拷贝到内存设备描述表中
StretchBlt(hMemDC,0,0,nWidth,nHeight,hScrDC,nX,nY,nWidth,nHeight,SRCCOPY);
//BitBlt(hMemDC, 0, 0, nWidth, nHeight,hScrDC, nX, nY, SRCCOPY);
//得到屏幕位图的句柄 hBitmap = (HBITMAP)SelectObject(hMemDC, hOldBitmap);
//清除 // DeleteDC(hScrDC);
DeleteDC(hMemDC);
DeleteObject(hOldBitmap);
// 返回位图句柄
return hBitmap;
}
void CDcToBmpView::OnSaveBMP()
{
CDC *pdc=GetDC();
HBITMAP hBmp;
pdc-> TextOut (100,100, "asfd ");
CRect rt(100,100,200,200); LPRECT lprt=&rt;
pdc-> Ellipse (rt); hBmp=CopyDCToBitmap(pdc-> GetSafeHdc (), lprt);
SaveBmp(hBmp, "f:\\1.bmp ");
}