//****************************************************************************
//* 名称：DDBToDIB
//* 作者：徐景周(jingzhou_xu@163.net)
//* 功能：设备相关转换为设备无关位图
//****************************************************************************
HANDLE CScreenSnapDlg::DDBToDIB( CBitmap& bitmap, DWORD dwCompression /*
= BI_RGB */)
{
BITMAP bm;
BITMAPINFOHEADER bi;
LPBITMAPINFOHEADER lpbi;
DWORD dwLen;
HANDLE hDIB;
HANDLE handle;
HDC hDC;
HPALETTE hPal;
CWindowDC dc( this );
CPalette pal;
//如果支持调色板的话，则建立它
if( dc.GetDeviceCaps( RASTERCAPS ) & RC_PALETTE )
{
UINT nSize = sizeof(LOGPALETTE) + ( sizeof(PALETTEENTRY) * 256 );
LOGPALETTE* pLP = (LOGPALETTE*)new BYTE[nSize];
pLP->palVersion = 0x300;
pLP->palNumEntries = (unsigned short)GetSystemPaletteEntries( dc, 0, 255,
pLP->palPalEntry );
pal.CreatePalette( pLP );
//释放
delete[] pLP;
}
ASSERT( bitmap.GetSafeHandle() );
//不支持BI_BITFIELDS类型
if( dwCompression == BI_BITFIELDS )
return NULL;
//如果调色板为空，则用默认调色板
hPal = (HPALETTE) pal.GetSafeHandle();
if (hPal==NULL)
hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE);
//获取位图信息
bitmap.GetObject(sizeof(bm),(LPSTR)&bm);
//初始化位图信息头
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bm.bmWidth;
bi.biHeight = bm.bmHeight;
bi.biPlanes = 1;
bi.biBitCount = (unsigned short)(bm.bmPlanes * bm.bmBitsPixel) ;
bi.biCompression = dwCompression;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0;
//计算信息头及颜色表大小
int nColors = 0;
if(bi.biBitCount <= 8)
{
nColors = (1 << bi.biBitCount);
}
dwLen = bi.biSize + nColors * sizeof(RGBQUAD);
hDC = ::GetDC(NULL);
hPal = SelectPalette(hDC,hPal,FALSE);
RealizePalette(hDC);
//为信息头及颜色表分配内存
hDIB = GlobalAlloc(GMEM_FIXED,dwLen);
if (!hDIB){
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
lpbi = (LPBITMAPINFOHEADER)GlobalLock(hDIB);
*lpbi = bi;
//调用 GetDIBits 计算图像大小
GetDIBits(hDC, (HBITMAP)bitmap.GetSafeHandle(), 0L, (DWORD)bi.biHeight,
(LPBYTE)NULL, (LPBITMAPINFO)lpbi, (DWORD)DIB_RGB_COLORS);
bi = *lpbi;
//图像的每一行都对齐(32bit)边界
if (bi.biSizeImage == 0){
bi.biSizeImage = ((((bi.biWidth * bi.biBitCount) + 31) &#38; ~31) / 8)
* bi.biHeight;
if (dwCompression != BI_RGB)
bi.biSizeImage = (bi.biSizeImage * 3) / 2;
}
//重新分配内存大小，以便放下所有数据
dwLen += bi.biSizeImage;
handle = GlobalReAlloc(hDIB, dwLen, GMEM_MOVEABLE) ;
if (handle != NULL)
hDIB = handle;
else
{
GlobalFree(hDIB);
//重选原始调色板
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
//获取位图数据
lpbi = (LPBITMAPINFOHEADER)hDIB;
//最终获得的DIB
BOOL bGotBits = GetDIBits( hDC, (HBITMAP)bitmap.GetSafeHandle(),
0L, //扫描行起始处
(DWORD)bi.biHeight, //扫描行数
(LPBYTE)lpbi //位图数据地址
+ (bi.biSize + nColors * sizeof(RGBQUAD)),
(LPBITMAPINFO)lpbi, //位图信息地址
(DWORD)DIB_RGB_COLORS); //颜色板使用RGB
if( !bGotBits )
{
GlobalFree(hDIB);
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return NULL;
}
SelectPalette(hDC,hPal,FALSE);
::ReleaseDC(NULL,hDC);
return hDIB;
}
//********************************************************************************
//* 名称：SaveBitmapToFile
//* 修改：徐景周(jingzhou_xu@163.net)
//* 功能：保存为位图文件
//********************************************************************************
BOOL CScreenSnapDlg::SaveBitmapToFile(HBITMAP hBitmap , CString lpFileName)
{
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， 位图中像素字节大小 ，位图文件大小 ， 写入文件字节数
dwBmBitsSize,
dwDIBSize, dwWritten;
BITMAP Bitmap;
BITMAPFILEHEADER bmfHdr;
//位图属性结构
BITMAPINFOHEADER bi;
//位图文件头结构
LPBITMAPINFOHEADER lpbi;
//位图信息头结构
HANDLE fh, hDib, hPal,hOldPal=NULL;
//指向位图信息头结构,定义文件，分配内存句柄，调色板句柄
//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 if (iBits <= 24)
wBitCount = 24;
//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)&#38;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(lpFileName, 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)&#38;bmfHdr, sizeof
(BITMAPFILEHEADER), &#38;dwWritten, NULL);
// 写入位图文件其余内容
WriteFile(fh, (LPSTR)lpbi, dwDIBSize,
&#38;dwWritten, NULL);
//消除内存分配
GlobalUnlock(hDib);
GlobalFree(hDib);
CloseHandle(fh);
return TRUE;
} |
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