摘要： 做ios网络开发的肯定会用到苹果的官方库Reachability。ios5发布了，将项目升级到ios5的过程发一个warning:+ (Reachability*) reachabilityWithAddress: (conststructsockaddr_in*) hostAddress;中Declaration of 'struct sockaddr_in' will not be visible outside of this function解决办法很简单，Reachability.h中最前面添加头文件:#import<netinet/in.h> 阅读全文