http请求必须是https的吗？普通的http请求，
1.模拟器报了这个信息：Simulator : Response failed, error buffer: The resource could not be loaded because the App Transport Security policy requires the use of a secure connection.
2.chrome浏览器也报错：XMLHttpRequest cannot load http://xxxxx/service/sync/time. No ‘Access-Control-Allow-Origin’ header is present on the requested resource. Origin ‘http://localhost:7456’ is therefore not allowed access.
官方的demo里确实也是用的https，那难度http就费了么？
请大神指导下，该怎么实现。