iOS判断手机是否有网的方法

#pragma mark 判断手机是否联网

- (BOOL)connectedToNetwork{

    

    //创建零地址，0.0.0.0的地址表示查询本机的网络连接状态

    

   struct sockaddr_storage zeroAddress;

    

   bzero(&zeroAddress, sizeof(zeroAddress));

    zeroAddress.ss_len =sizeof(zeroAddress);

    zeroAddress.ss_family =AF_INET;

    

    // Recover reachability flags

   SCNetworkReachabilityRef defaultRouteReachability =SCNetworkReachabilityCreateWithAddress(NULL, (structsockaddr *)&zeroAddress);

    SCNetworkReachabilityFlags flags;

    

    //获得连接的标志

   BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);

   CFRelease(defaultRouteReachability);

    

    //如果不能获取连接标志，则不能连接网络，直接返回

   if (!didRetrieveFlags)

    {

       return NO;

    }

    //根据获得的连接标志进行判断

    

   BOOL isReachable = flags & kSCNetworkFlagsReachable;

    BOOL needsConnection = flags &kSCNetworkFlagsConnectionRequired;

   return (isReachable&&!needsConnection) ? YES : NO;

}