json文件的读取与保存

std::string levelpath = FileUtils::getInstance()->fullPathForFilename("leveldata");    const char* filepath = levelpath.c_str();    std::string filestr = FileUtils::getInstance()->getStringFromFile(filepath);    std::string writePath = FileUtils::getInstance()->getWritablePath()+"leveldata";    if (!FileUtils::getInstance()->isFileExist(writePath)) {        FILE* openFile = fopen(writePath.c_str(), "wb+");        fwrite(filestr.c_str(), 1, filestr.size(), openFile);        fclose(openFile);    }    filestr = FileUtils::getInstance()->getStringFromFile(writePath.c_str());

读取文件，写入沙盒