WinCE 截屏 - C++ 代碼

浅浅的花香味﹌ 2022-04-06 14:14 203阅读 0赞

// this function create a bmp file to save the current screen;
    // supported eVC++ 4.0 (wince 4.0) and vc++ 6.0 , test pass; 
    void CSnapDlg::OnScreenSave(const char *filename)
    { 
        HDC  hScrDC, hMemDC;         
        int  width, height; 
    
     //the pointer will save all pixel point's color value
     BYTE  *lpBitmapBits = NULL; 
    
     //creates a device context for the screen device
        hScrDC = CreateDC(_T("DISPLAY"), NULL, NULL, NULL);
    
      //get the screen point size
        width = GetDeviceCaps(hScrDC, HORZRES);
        height = GetDeviceCaps(hScrDC, VERTRES);
    
        //creates a memory device context (DC) compatible with the screen device(hScrDC)  
        hMemDC = CreateCompatibleDC(hScrDC);
    
     //initialise the struct BITMAPINFO for the bimap infomation， 
     //in order to use the function CreateDIBSection
     // on wince os, each pixel stored by 24 bits(biBitCount=24) 
     //and no compressing(biCompression=0) 
        BITMAPINFO RGB24BitsBITMAPINFO; 
        ZeroMemory(&RGB24BitsBITMAPINFO, sizeof(BITMAPINFO));
        RGB24BitsBITMAPINFO.bmiHeader.biSize = sizeof(BITMAPINFOHEADER);
        RGB24BitsBITMAPINFO.bmiHeader.biWidth = width;
        RGB24BitsBITMAPINFO.bmiHeader.biHeight = height;
        RGB24BitsBITMAPINFO.bmiHeader.biPlanes = 1;
        RGB24BitsBITMAPINFO.bmiHeader.biBitCount = 24;
    
      //use the function CreateDIBSection and SelectObject 
     //in order to get the bimap pointer : lpBitmapBits 
        HBITMAP directBmp = CreateDIBSection(hMemDC, (BITMAPINFO*)&RGB24BitsBITMAPINFO, 
           DIB_RGB_COLORS, (void **)&lpBitmapBits, NULL, 0);
     HGDIOBJ previousObject = SelectObject(hMemDC, directBmp);
    
     // copy the screen dc to the memory dc
     BitBlt(hMemDC, 0, 0, width, height, hScrDC, 0, 0, SRCCOPY);
    
     //if you only want to get the every pixel color value, 
     //you can begin here and the following part of this function will be unuseful;
     //the following part is in order to write file;
    
     //bimap file header in order to write bmp file 
     BITMAPFILEHEADER bmBITMAPFILEHEADER;
     ZeroMemory(&bmBITMAPFILEHEADER, sizeof(BITMAPFILEHEADER));
     bmBITMAPFILEHEADER.bfType = 0x4d42;  //bmp  
        bmBITMAPFILEHEADER.bfOffBits = sizeof(BITMAPFILEHEADER) + sizeof(BITMAPINFOHEADER);
        bmBITMAPFILEHEADER.bfSize = bmBITMAPFILEHEADER.bfOffBits + ((width*height)*3); ///3=(24 / 8)
    
     //write into file
     FILE *mStream = NULL;
     if((mStream = fopen(filename, "wb")))
     {  
      //write bitmap file header
      fwrite(&bmBITMAPFILEHEADER, sizeof(BITMAPFILEHEADER), 1, mStream);
      //write bitmap info
      fwrite(&(RGB24BitsBITMAPINFO.bmiHeader), sizeof(BITMAPINFOHEADER), 1, mStream);
      //write bitmap pixels data
      fwrite(lpBitmapBits, 3*width*height, 1, mStream);
       //close file
      fclose(mStream);
     }
    
     //delete
     DeleteObject(hMemDC);
     DeleteObject(hScrDC);
     DeleteObject(directBmp);
     DeleteObject(previousObject);
    }