通过 cocos2dx 的 httpRequest 访问云方法返回 401错误，什么原因呢？

   auto request = new HttpRequest();
    request->setRequestType(HttpRequest::Type::POST);
    request->setUrl("https://api.leancloud.cn/1.1/functions/" + cloudMethod);
    std::vector<std::string> headers;
    headers.push_back("X-LC-Id:"+ std::string(LeanCloudHelper::getApplicationId()));
    headers.push_back("X-LC-Key:"+std::string(LeanCloudHelper::getClientKey()));
    headers.push_back("X-LC-Session:"+std::string(LeanCloudHelper::getUserSessionToken()));
    headers.push_back("Content-Type:application/json");
    request->setHeaders(headers);
    return request;