带fwrite的内存QFile

我不想去文件系统保存和读回PGM映像文件,而是想在内存中这样做。我是否可以使用QBuffer作为内存中的QFile来绕过保存到文件系统:

            QFile filename(QString("/home/pi/frame-%1.pgm").arg(i));
            bool didOpen = filename.open(QIODevice::ReadWrite);
            qDebug() << "Did open file: " << didOpen << filename.fileName();
            int fileHandle = filename.handle();
            FILE * f = fdopen(dup(fileHandle), "wb");
            int res = fprintf(f, "P5 %d %d 65535\n", w, h);
            for (int y = 0; y < h; y++) {
                for (int x = 0; x < w; x++) {
                    uint16_t v = img[y*w+x];
                    //v = htobe16(v);
                    res = fwrite((uint8_t*)&v, sizeof(uint16_t), 1, f);
                }
            }
            fclose(f);

            QPixmap pixmap;
            bool didLoad = pixmap.load(QString("/home/pi/frame-%1.pgm").arg(i));
            emit updateScreen(pixmap);