写入文件

        QFile file(path);if (file.open(QIODevice::WriteOnly)) {// 将 QImage 保存到文件file.write(jsonData.toByteArray());// 关闭文件file.close();SCDebug << "saved to" << path;} else {SCDebug << "Failed to open file for writing"<< file.errorString();}

截取数据
参考：【QT学习笔记】QByteArray 截取数据