c++ - Can't save PNG image into file -

i have troubles image saving. have crop "1.png" rect , save file, empty 1 appearing (0 bytes). doing wrong?

void redactorform::cropbuttonslot(int x1, int y1, int x2, int y2) {      qimage pixmap("1.png");     qrect rect(x1,y1,x2,y2);     pixmap=pixmap.copy(rect);      qstring filename("d:/yourfile.png");     qfile file(filename);     file.open(qiodevice::writeonly);      qdatastream out(&file);     pixmap.save(filename,0,100);     out <<pixmap; } 

qimage's save method not take file name parameter, taske qfile. try this;

    pixmap.save(&file, "png");