c++ - Taking screenshots -

i have problem taking screenshots. fine, have problem in resolution 1366x768. bitmap broken , can't open file.

hdc _dc = getwindowdc(okno);  szer_wys(); //ustawia szerokosc wysokosc aktywnego ekranu  dc = createcompatibledc( 0 ); bm = createcompatiblebitmap( _dc, w, h ); selectobject( dc, bm ); stretchblt( dc, 0, 0, w, h, _dc, 0, 0, w, h, srccopy );  getobject( bm, 84, buf ); ddd = getdc( 0 ); dc2 = createcompatibledc( ddd );  tagbitmapinfo bit_info; //tworzy obiekt na strukture  bit_info.bmiheader.bisize = sizeof( bit_info.bmiheader );  //rozmiar struktury bmiheader (40 ) bit_info.bmiheader.biwidth = w; //szerokość bitmapy w pikselac bit_info.bmiheader.biheight = h;  //wysokosc bitmapy w pikselac bit_info.bmiheader.biplanes = 1;   bit_info.bmiheader.bibitcount = 24; //liczba bitów kodujących piksel (rgb) bit_info.bmiheader.bicompression = 0; //0 - brak wewnętrznej kompresji bit_info.bmiheader.bisizeimage = 0;   h_createdib = createdibsection( dc, & bit_info, dib_rgb_colors, & buf, 0, 0 );                 getdibits( dc, bm, 0, h, buf, & bit_info, dib_rgb_colors );   bitmapfileheader bit_header; bit_header.bftype = makeword( 'b', 'm' ); //typ pliku bit_header.bfsize = w * h * 3 + 54; //w * h * 3 kolory + nagłówek  bit_header.bfoffbits = 54;  bitmapinfoheader bit_info_header; bit_info_header.bisize = 40; bit_info_header.biwidth = w; bit_info_header.biheight = h; bit_info_header.biplanes = 0; bit_info_header.bibitcount = 24; bit_info_header.bicompression = 0; bit_info_header.bisizeimage = w * h * 3;   sciezka = obiekt.pobierzpathscreen() +  obiekt.pobierznazwe() + ".bmp";         ofstream plik(sciezka, ios::binary); if(plik.good()) {         plik.write(reinterpret_cast<char*>(&bit_header), sizeof(bit_header));         plik.write(reinterpret_cast<char*>(&bit_info_header), sizeof(bit_info_header));         plik.write(reinterpret_cast<char*>(buf), w*h*3 );  }else cout<<"blad pliku";  plik.close(); 

*szer_wys()* reading screen resolution.

edit

i changed content of szer_wys() this:

void zrzut::szer_wys() {     rect re;     getwindowrect( okno, & re );     w = re.right, h = re.bottom;      while(w%4 != 0)     {             w++;     } } 

and works fine :)

the count of bytes per line in bitmap must multiple of 4. in case

(3*1366)/4=1024,5 not multiple of 4 

you have save line line, padding 2 bytes each line. keep in mind change bisizeimage , bfsize member not width , height of image. can avoid problem if use 32bit per pixel.