如何实现屏幕抓屏并保存为BMP位图文件？？

这是我以前研究的代码。
可以抓屏显示到view中。不过没有实现保存
lz参考下吧
void CNetControlView::OnActionPrintscreen()
{
// TODO: Add your command handler code here
HANDLE hDib;
HBITMAP hBit;
POINT BitScale; BitScale.x = BMPWIDTH;
BitScale.y = BMPHEIGHT; //截图
hBit = GetSrcBit(BitScale.x,BitScale.y); //位图转换
hDib = DDBtoDIB(hBit); DWORD bitSize = GlobalSize(hDib); //显示位图
HDC hdc;
HDC hdcmem;
RECT rect;
HBITMAP hbitmap;
HBITMAP hbitmapOld; hbitmap = (HBITMAP)hDib; hdc = ::GetDC(this->m_hWnd);
::GetClientRect(this->m_hWnd,&rect);
hdcmem=CreateCompatibleDC(hdc);
hbitmapOld=(HBITMAP)SelectObject(hdcmem,hBit);
SetStretchBltMode(hdc, STRETCH_HALFTONE);
StretchBlt(hdc,0,0,BMPWIDTH,BMPHEIGHT,hdcmem,0,0,BMPWIDTH_2,BMPHEIGHT_2,SRCCOPY); //CClientDC dc(this);
//dc.MoveTo(0,0);
//dc.LineTo(50,50); SelectObject(hdcmem,hbitmapOld);
DeleteObject(hbitmap);
DeleteDC(hdcmem);
::ReleaseDC(this->m_hWnd,hdc);
    DeleteDC(hdc); SetBitmap(hBit);
m_nFirstDraw++;
}HBITMAP CNetControlView::GetSrcBit(DWORD BitWidth, DWORD BitHeight)//截图,用桌面HDC覆盖HBITMAP
{
HDC hdcmy;
HDC hbufferdc;
HBITMAP hBit;
HBITMAP hOldBitmap; //Create DesktopDC
hdcmy = CreateDC("DISPLAY",NULL,NULL,NULL);//creates a device context (DC) for a device by using the specified name "DISPLAY" for a display driver
hbufferdc = CreateCompatibleDC(hdcmy);// creates a memory device context (DC) compatible with the specified device. //Create Hbitmap
hBit = CreateCompatibleBitmap(hdcmy, BitWidth, BitHeight);// creates a bitmap compatible with the device that is associated with the specified device context. //Get bit to Buffer
hOldBitmap = (HBITMAP)SelectObject(hbufferdc, hBit);
StretchBlt(hbufferdc, 0, 0, BitWidth, BitHeight,
hdcmy, 0, 0,BitWidth,BitHeight, SRCCOPY); //Get finally bit
hBit = (HBITMAP)SelectObject(hbufferdc, hOldBitmap);

//Release Memory
DeleteObject(hOldBitmap);
//ReleaseDC(NULL,hdcmy);
//ReleaseDC(NULL,hbufferdc);
::ReleaseDC(NULL,hdcmy);
::ReleaseDC(NULL,hbufferdc);

return hBit;
}HANDLE CNetControlView::DDBtoDIB(HBITMAP bitmap)
{
//Define Variable
BITMAP bm;
BITMAPINFOHEADER   bi;
  LPBITMAPINFOHEADER lpbi;
DWORD    dwLen;
HANDLE hDib;
HANDLE handle;
HDC    hdc;
HPALETTE hPal; hPal = (HPALETTE) GetStockObject(DEFAULT_PALETTE ); // get bitmap information
GetObject(bitmap,sizeof(bm),(LPSTR)&bm); // initialize the bitmapinfoheader
bi.biSize = sizeof(BITMAPINFOHEADER);
bi.biWidth = bm.bmWidth;
bi.biHeight = bm.bmHeight;
bi.biPlanes = 1;
//bi.biBitCount = bm.bmPlanes * bm.bmBitsPixel;
bi.biBitCount = 8;
bi.biCompression = BI_RGB;
bi.biSizeImage = 0;
bi.biXPelsPerMeter = 0;
bi.biYPelsPerMeter = 0;
bi.biClrUsed = 0;
bi.biClrImportant = 0; // compute the size of the  infoheader and the color table
int ncolors = (1 << bi.biBitCount);
dwLen  = bi.biSize + ncolors * sizeof(RGBQUAD); // we need a device context to get the dib from
hdc = ::GetDC(NULL);
hPal = SelectPalette(hdc,hPal,FALSE);
RealizePalette(hdc); // allocate enough memory to hold bitmapinfoheader and color table
hDib = GlobalAlloc(GMEM_FIXED,dwLen); if (!hDib){
SelectPalette(hdc,hPal,FALSE);
::ReleaseDC(NULL,hdc);
return NULL;
} lpbi = (LPBITMAPINFOHEADER)hDib; *lpbi = bi; // call getdibits with a NULL lpbits param, so the device driver
// will calculate the bisizeimage field
GetDIBits(hdc, bitmap, 0L, (DWORD)bi.biHeight,
(LPBYTE)NULL, (LPBITMAPINFO)lpbi, (DWORD)DIB_RGB_COLORS ); bi = *lpbi; // if the driver did not fill in the bisizeimage field, then compute it
// each scan line of the image is aligned on a dword (32bit) boundary
if (bi.biSizeImage == 0)
{
bi.biSizeImage = ((((bi.biWidth * bi.biBitCount) + 31) & ~31) / 8)
* bi.biHeight;
} // realloc the buffer so that it can hold all the bits
dwLen += bi.biSizeImage;
if (handle = GlobalReAlloc(hDib, dwLen, GMEM_MOVEABLE))
hDib = handle;
else
{
GlobalFree(hDib); // reselect the original palette
SelectPalette(hdc,hPal,FALSE);
::ReleaseDC(NULL,hdc);
return NULL;
} // get the bitmap bits
lpbi = (LPBITMAPINFOHEADER)hDib; // finally get the dib
BOOL bgotbits = GetDIBits( hdc, bitmap,
0L, // start scan line
(DWORD)bi.biHeight, // # of scan lines
(LPBYTE)lpbi // address for bitmap bits
+ (bi.biSize + ncolors * sizeof(RGBQUAD)),
(LPBITMAPINFO)lpbi, // address of bitmapinfo
(DWORD)DIB_RGB_COLORS); // use rgb for color table if( !bgotbits )
{
GlobalFree(hDib);

SelectPalette(hdc,hPal,FALSE);
::ReleaseDC(NULL,hdc);
return NULL;
} SelectPalette(hdc,hPal,FALSE);
::ReleaseDC(NULL,hdc);
return hDib;
}void CNetControlView::SetBitmap(HBITMAP bmp)
{
m_CurrentBmp = bmp;
}
用gdi+抓屏并存成.jpg文件#include  <windows.h>
#include  <gdiplus.h>
#include  <stdio.h>

using  namespace  Gdiplus;

#pragma  comment  (lib,  "gdiplus.lib")

GdiplusStartupInput  gdiplusStartupInput;
ULONG_PTR                      gdiplusToken;

int  GetEncoderClsid(LPCWSTR  format,  CLSID*  pClsid)
{
       UINT    num  =  0;
       UINT    size  =  0;

       ImageCodecInfo*  pImageCodecInfo  =  NULL;

       GetImageEncodersSize(&num,  &size);
       if(size  ==  0)
               return  -1;

       pImageCodecInfo  =  (ImageCodecInfo*)(malloc(size));
       if(pImageCodecInfo  ==  NULL)
               return  -1;

       GetImageEncoders(num,  size,  pImageCodecInfo);

       for(UINT  j  =  0;  j  <  num;  ++j)
       {
               if(  wcscmp(pImageCodecInfo[j].MimeType,  format)  ==  0  )
               {
                       *pClsid  =  pImageCodecInfo[j].Clsid;
                       free(pImageCodecInfo);
                       return  j;
               }
       }

       free(pImageCodecInfo);
       return  -1;
}
//    参数
//            xs  =  图象x轴大小
//            ys  =  图象y轴大小
//            quality  =  jpeg图象质量

VOID        SaveCurScreenJpg(LPCWSTR  pszFileName,  int  xs,  int  ys,  int  quality)
{
       HWND        hwnd  =  ::GetDesktopWindow();
       HDC          hdc  =  GetWindowDC(NULL);
       int          x  =  GetDeviceCaps(hdc,  HORZRES);
       int          y  =  GetDeviceCaps(hdc,  VERTRES);
       HBITMAP  hbmp  =  ::CreateCompatibleBitmap(hdc,  x,  y),  hold;
       HDC          hmemdc  =  ::CreateCompatibleDC(hdc);
       hold        =  (HBITMAP)::SelectObject(hmemdc,  hbmp);
       BitBlt(hmemdc,  0,  0,  x,  y,  hdc,  0,  0,  SRCCOPY);
       SelectObject(hmemdc,  hold);
       {
               Bitmap    bit(xs,  ys),  bit2(hbmp,  NULL);
               Graphics        g(&bit);
               g.ScaleTransform((float)xs/x,  (float)ys/y);
               g.DrawImage(&bit2,  0,  0);

               CLSID                          encoderClsid;
               EncoderParameters  encoderParameters;

               encoderParameters.Count  =  1;
               encoderParameters.Parameter[0].Guid  =  EncoderQuality;
               encoderParameters.Parameter[0].Type  =  EncoderParameterValueTypeLong;
               encoderParameters.Parameter[0].NumberOfValues  =  1;
               encoderParameters.Parameter[0].Value  =  &quality;

               GetEncoderClsid(L"image/jpeg",  &encoderClsid);
               bit.Save(pszFileName,  &encoderClsid,  &encoderParameters);
       }
       ::DeleteObject(hbmp);
       ::DeleteObject(hmemdc);
       return;
}
int  APIENTRY  WinMain(HINSTANCE  hInstance,
                                         HINSTANCE  hPrevInstance,
                                         LPSTR          lpCmdLine,
                                         int              nCmdShow)
{
       GdiplusStartup(&gdiplusToken,  &gdiplusStartupInput,  NULL);
       ::SaveCurScreenJpg(L".\\cap.400.300.30.jpg",  400,  300,  30);
       ::SaveCurScreenJpg(L".\\cap.800.600.100.jpg",  800,  600,  100);
       ::SaveCurScreenJpg(L".\\cap.800.600.100.jpg",  640,  480,  50);
       GdiplusShutdown(gdiplusToken);

       return  0;
}
//把指定HDC存放为指定大小指定比例指定类型文件
VOID SaveHdcToImageFile(LPCWSTR pszFileName,HDC hdc, int startX, int startY, int xSize, int ySize, float fScaleX=1,float fScaleY =1, LPCWSTR format=L"image/jpeg")
{
int x = GetDeviceCaps(hdc, HORZRES);
int y = GetDeviceCaps(hdc, VERTRES);
HBITMAP hbmp = ::CreateCompatibleBitmap(hdc, x, y);
HDC hmemdc = ::CreateCompatibleDC(hdc);
HBITMAP hold = (HBITMAP)::SelectObject(hmemdc, hbmp);
BitBlt(hmemdc, 0, 0, xSize, ySize, hdc, startX, startY, SRCCOPY);
SelectObject(hmemdc, hold);

Bitmap bit(xSize*fScaleX, ySize*fScaleY);
Bitmap bit2(hbmp, NULL);
Graphics g(&bit);
g.ScaleTransform(fScaleX, fScaleY);
g.DrawImage(&bit2, 0, 0); CLSID encoderClsid; GetEncoderClsid(format, &encoderClsid);
bit.Save(pszFileName, &encoderClsid, NULL);

::DeleteObject(hbmp);
::DeleteObject(hmemdc);
return;
}
http://blog.csdn.net/bobob/上面有篇文章，可截取屏幕指定区域图片并存为bmp文件。自己稍加改动，就可以用了。

调试易

如何实现屏幕抓屏并保存为BMP位图文件？？

解决方案 »