项目中需要用到的功能。

void Screenshot(){    CDC *pDC;    pDC = CDC::FromHandle(GetDC(GetDesktopWindow()));    if(pDC == NULL)        return;    int BitPerPixel = pDC->GetDeviceCaps(BITSPIXEL);    int Width = pDC->GetDeviceCaps(HORZRES);    int Height = pDC->GetDeviceCaps(VERTRES);    CDC memDC;    if(memDC.CreateCompatibleDC(pDC) == 0)        return;    CBitmap memBitmap, *oldmemBitmap;    if(memBitmap.CreateCompatibleBitmap(pDC, Width, Height) == NULL)        return;    oldmemBitmap = memDC.SelectObject(&memBitmap);    if(oldmemBitmap == NULL)        return;    if(memDC.BitBlt(0, 0, Width, Height, pDC, 0, 0, SRCCOPY) == 0)        return;    CPoint po;    GetCursorPos(&po);    HICON hinco = (HICON)GetCursor();    memDC.DrawIcon(po.x-10 , po.y - 10 , hinco);    BITMAP bmp;    memBitmap.GetBitmap(&bmp);    BITMAPINFOHEADER bih = {
   0};    bih.biBitCount = bmp.bmBitsPixel;    bih.biCompression = BI_RGB;    bih.biHeight = bmp.bmHeight;    bih.biPlanes = 1;    bih.biSize = sizeof(BITMAPINFOHEADER);    bih.biSizeImage = bmp.bmWidthBytes * bmp.bmHeight;    bih.biWidth = bmp.bmWidth;    BITMAPFILEHEADER bfh = {
   0};    bfh.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);    bfh.bfSize = bfh.bfOffBits + bmp.bmWidthBytes * bmp.bmHeight;    bfh.bfType = (WORD)0x4d42;    BYTE* pImgBuff = new BYTE[bmp.bmWidthBytes * bmp.bmHeight];    GetDIBits(memDC.m_hDC, (HBITMAP) memBitmap.m_hObject        , 0, Height, pImgBuff, (LPBITMAPINFO) &bih, DIB_RGB_COLORS);    memDC.SelectObject(oldmemBitmap);    BYTE* pJpg = NULL;    int nJpgSize = BmpToJpeg(pImgBuff, bmp.bmWidth, bmp.bmHeight, &pJpg);    if (NULL != pJpg)    {        delete[] pJpg;    }    delete [] pImgBuff;}

附上 BmpToJpeg

int BmpToJpeg(BYTE *pSrc, int nWidth, int nHeight, BYTE** ppDes){    struct jpeg_compress_struct cinfo;    struct jpeg_error_mgr jerr;    JSAMPROW row_pointer[1];    int row_stride;    cinfo.err = jpeg_std_error(&jerr);    jpeg_create_compress(&cinfo);    DWORD dwLen = nWidth * nHeight * 3;    jpeg_mem_dest(&cinfo, ppDes, &dwLen);    cinfo.image_width = nWidth;    cinfo.image_height = nHeight;    cinfo.input_components = 3;    cinfo.in_color_space = JCS_RGB;    jpeg_set_defaults(&cinfo);    jpeg_set_quality(&cinfo, JPEG_QUALITY, TRUE);    jpeg_start_compress(&cinfo, TRUE);    row_stride = nWidth * 3;    for (int i=0, j=0; j < nWidth*nHeight*4; i+=3, j+=4)    //BGRA => RGB    {        *(pSrc+i)=*(pSrc+j+2);        *(pSrc+i+1)=*(pSrc+j+1);        *(pSrc+i+2)=*(pSrc+j);    }    while (cinfo.next_scanline < cinfo.image_height)    {        row_pointer[0] = &pSrc[(cinfo.image_height - cinfo.next_scanline - 1) * row_stride];        (void) jpeg_write_scanlines(&cinfo, row_pointer, 1);    }    jpeg_finish_compress(&cinfo);    jpeg_destroy_compress(&cinfo);    return dwLen;}

需要用到的头文件

#define JPEG_QUALITY 50extern "C"{#include "jpeglib.h"#include "jmorecfg.h"#include "jconfig.h"}