8-3 我不愿意成为你退而求其次的人

Reachability

1.下载，添加Reachability类
2.为项目添加SystemConfiguration.Framework

Reachability* reach = [Reachability reachabilityWithHostname:@"www.google.com"];

// Tell the reachability that we DON'T want to be reachable on 3G/EDGE/CDMA
reach.reachableOnWWAN = NO;

[[NSNotificationCenter defaultCenter] addObserver:self
                                         selector:@selector(reachabilityChanged:)
                                             name:kReachabilityChangedNotification
                                           object:nil];

[reach startNotifier];


- (void)reachabilityChanged:(NSNotification *)note
{
    Reachability* curReach = [note object];
    
    NSParameterAssert([curReach isKindOfClass:[Reachability class]]);
    NetworkStatus netStatus = [curReach currentReachabilityStatus];
    
    switch (netStatus)
    {
        case NotReachable:      // 无网络
        {
            break;
        }
        case ReachableViaWWAN:  // 通过2G/3G/4G连接
        case ReachableViaWiFi:  // 通过Wifi连接
        {
            //网络变化时要注意验证用户身份
            [self authentication];
            
            break;
        }
    }
}

AFNetWorking

 1.下载安装AFNetWorking

//  网络连接单例
AFNetworkReachabilityManager *reachabilityManager = [AFNetworkReachabilityManager sharedManager];
//  打开检测
[reachabilityManager startMonitoring];

// 检测网络连接的代码块回调
[reachabilityManager setReachabilityStatusChangeBlock:^(AFNetworkReachabilityStatus status) {
   if (status == AFNetworkReachabilityStatusNotReachable) {
       //网络无连接的提示
   }
}];

// 网络连接状态
typedef NS_ENUM(NSInteger, AFNetworkReachabilityStatus) {
   AFNetworkReachabilityStatusUnknown          = -1, //未知
   AFNetworkReachabilityStatusNotReachable     = 0,  //无连接
   AFNetworkReachabilityStatusReachableViaWWAN = 1,  //3G
   AFNetworkReachabilityStatusReachableViaWiFi = 2,  //WIFI
};

YYKit

待定~