对于iOS复制，精选ios编程学习，很好的参考资料。-For iOS replication, selection of learning IOS programming, a good reference.

在iOS开发中经常要考虑到手机当前的网络状态，是在3G还是WIFI条件下，虽然iOS提供了访问手机网络状态的接口，但是该接口使用复制，而且经常频繁调用，本代码是被广泛使用的网络状态检测功能，使用方便-In iOS developers often have to take into account the current state of the network the phone is in 3G or WIFI condition, although iOS provides access