實時網絡狀態判斷

    AFNetworkReachabilityManager *manager = [AFNetworkReachabilityManager sharedManager];
    [manager startMonitoring];
    [manager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
        switch (status) {
                /*
                typedef NS_ENUM(NSInteger, AFNetworkReachabilityStatus) {
                    AFNetworkReachabilityStatusUnknown          = -1, //未知
                    AFNetworkReachabilityStatusNotReachable     = 0,  //無連接
                    AFNetworkReachabilityStatusReachableViaWWAN = 1,  //3G
                    AFNetworkReachabilityStatusReachableViaWiFi = 2,  //WIFI
                };
                 */
            case AFNetworkReachabilityStatusUnknown:
            {
                NSLog(@"未知網絡");
            }
                break;
            case AFNetworkReachabilityStatusNotReachable:
            {
                NSLog(@"無法聯網");
            }
                break;
                
            case AFNetworkReachabilityStatusReachableViaWWAN:
            {
                NSLog(@"手機網絡");
            }
                break;
            case AFNetworkReachabilityStatusReachableViaWiFi:
            {
                NSLog(@"WIFI");
            }
                
        }
    }];