-(void)afn{

 //1.创建网络状态监测管理者

 AFNetworkReachabilityManager *manger = [AFNetworkReachabilityManager sharedManager];

 //开启监听，记得开启，不然不走block

 [manger startMonitoring];

 //2.监听改变

 [manger setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {

 /*

 AFNetworkReachabilityStatusUnknown = -1,

 AFNetworkReachabilityStatusNotReachable = 0,

 AFNetworkReachabilityStatusReachableViaWWAN = 1,

 AFNetworkReachabilityStatusReachableViaWiFi = 2,

 */

 switch (status) {

 case AFNetworkReachabilityStatusUnknown:

 NSLog(@"未知");

 break;

 case AFNetworkReachabilityStatusNotReachable:

 NSLog(@"没有网络");

 break;

 case AFNetworkReachabilityStatusReachableViaWWAN:

 NSLog(@"3G|4G");

 break;

 case AFNetworkReachabilityStatusReachableViaWiFi:

 NSLog(@"WiFi");

 break;

 default:

 break;

 }

 }];

 }