怎么样把CD上的一个图保存为bmp格式的图？（用编程的方法）

[citywolf]

我用CBitmap.LoadBitmap函数，把一个bmp图显示在CDialog上，现在我要把CDialog上的这个图保存为另外一个bmp的文件名，怎么做？能否给出源代码

[citywolf]

bluebohe(薄荷):
我正在欣赏你的代码，解决后，至少给你80分：）

[yintongshun]

Writing a bitmap to a BMP file

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Writing a bitmap to a BMP file is fairly simple if we have a handle to device-independent bitmap. We simply write BITMAPINFOHEADER information followed by the contents of the bitmap. The three fields that we have to set in the BITMAPINFOHEADER are the bfType which should always be "BM", the bfSize which is the size of the bitmap including the infoheader and the bfOffBits which is the offset to the bitmap bits from the start of the file.
If you have a device-dependent bitmap to begin with, you have to first create a DIB from it. Creating a DIB from a DDB has already been covered in another section.

// WriteDIB - Writes a DIB to file
// Returns - TRUE on success
// szFile - Name of file to write to
// hDIB - Handle of the DIB
BOOL WriteDIB( LPTSTR szFile, HANDLE hDIB)
{
BITMAPFILEHEADER hdr;
LPBITMAPINFOHEADER lpbi;

if (!hDIB)
return FALSE;

CFile file;
if( !file.Open( szFile, CFile::modeWrite|CFile::modeCreate) )
return FALSE;

lpbi = (LPBITMAPINFOHEADER)hDIB;

int nColors = 1 << lpbi->biBitCount;

// Fill in the fields of the file header
hdr.bfType = ((WORD) ('M' << 8) | 'B'); // is always "BM"
hdr.bfSize = GlobalSize (hDIB) + sizeof( hdr );
hdr.bfReserved1 = 0;
hdr.bfReserved2 = 0;
hdr.bfOffBits = (DWORD) (sizeof( hdr ) + lpbi->biSize +
nColors * sizeof(RGBQUAD));

// Write the file header
file.Write( &hdr, sizeof(hdr) );

// Write the DIB header and the bits
file.Write( lpbi, GlobalSize(hDIB) );

return TRUE;
}

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[bluebohe]

// CReadWriteBmpView message handlers
HBITMAP GetSrcBit(HDC hDC,DWORD BitWidth, DWORD BitHeight)
{
HDC hBufDC;
HBITMAP hBitmap, hBitTemp;

//创建设备上下文(HDC)
hBufDC = CreateCompatibleDC(hDC);

//创建HBITMAP
hBitmap = CreateCompatibleBitmap(hDC, BitWidth, BitHeight);
hBitTemp = (HBITMAP) SelectObject(hBufDC, hBitmap);

//得到位图缓冲区
StretchBlt(hBufDC, 0, 0, BitWidth, BitHeight,
hDC, 0, 0, BitWidth, BitHeight, SRCCOPY);

//得到最终的位图信息
hBitmap = (HBITMAP) SelectObject(hBufDC, hBitTemp);

//释放内存

DeleteObject(hBitTemp);
::DeleteDC(hBufDC);

return hBitmap;
}

BOOL SaveBmp(HBITMAP hBitmap, CString FileName)
{
//设备描述表
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);
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;
}

[fingerfox]

DIBAPI