李国帅 编写于2011年4月
int CGoogleMapDlg::SaveBitmapToFile()
{
TCHAR UserProfile[MAX_PATH];
memset(UserProfile, 0, sizeof(TCHAR)*MAX_PATH);
GetEnvironmentVariable(_T("USERPROFILE"), UserProfile, MAX_PATH);
_tcscat_s(UserProfile,MAX_PATH, _T("\\My Documents\\"));
SYSTEMTIME timeNow;
GetLocalTime(&timeNow);
TCHAR FileName[MAX_PATH];
memset(FileName, 0, sizeof(FileName));
_sntprintf_s(FileName,MAX_PATH, MAX_PATH-1, _T("%04d%02d%02d%02d%02d%02d.bmp"), timeNow.wYear, timeNow.wMonth, timeNow.wDay, timeNow.wHour, timeNow.wMinute, timeNow.wSecond);
_tcscat_s(UserProfile,MAX_PATH, FileName);
LPSTR lpFileName = UserProfile;//为位图文件名
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
//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, dwDIBSize, dwWritten;
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, hDib ; //定义文件，分配内存句柄
HPALETTE hPal,hOldPal=NULL;//调色板句柄
CDC dc;
HDC hdc = ::GetDC(m_hWnd);
dc.Attach(hdc);
CDC memDC;
memDC.CreateCompatibleDC(&dc);
CRect r;
GetClientRect(&r);
CSize sz(r.Width(), r.Height());
CBitmap bm;
bm.CreateCompatibleBitmap(&dc, sz.cx, sz.cy);
CBitmap* oldBitmap = memDC.SelectObject(&bm);
memDC.BitBlt(0, 0, sz.cx, sz.cy, &dc, 0, 0, SRCCOPY);
HBITMAP hBitmap = (HBITMAP)bm;//hBitmap 为刚才的屏幕位图句柄
//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;
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 = (HPALETTE)GetStockObject(DEFAULT_PALETTE);
if(hPal)
{
hDC = ::GetDC(NULL);
hOldPal = SelectPalette(hDC, 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, 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)
{
// 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);
memDC.SelectObject(oldBitmap);
bm.Detach(); // make sure bitmap not deleted with CBitmap object
return 0;
}
