获取外网ip

第一个方法

NSURL *ipURL = [NSURL URLWithString:@"http://ip.taobao.com/service/getIpInfo2.php?ip=myip"];

NSData *data = [NSData dataWithContentsOfURL:ipURL];

NSDictionary *ipDic = [NSJSONSerialization JSONObjectWithData:data options:NSJSONReadingMutableContainers error:nil];

NSString *ipStr = nil;
if (ipDic && [ipDic[@"code"] integerValue] == 0) {
    ipStr = ipDic[@"data"][@"ip"];
}

第二种方法

NSError *error;

NSURL *ipURL = [NSURL URLWithString:@"http://ifconfig.me/ip"];

NSString *ip = [NSString stringWithContentsOfURL:ipURL encoding:NSUTF8StringEncoding error:&error];

NSUserDefaults *defaults = [NSUserDefaults standardUserDefaults];

[defaults setObject:ip forKey:@"netWorkIP"];