iOS监听网络变化

首先项目中包含框架

然后在delegate中： 

//初始化添加网络

- (BOOL)application:(UIApplication *)application didFinishLaunchingWithOptions:(NSDictionary *)launchOptions {

    //开启网络状况的监听

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

    

   Reachability* hostReach = [Reachability reachabilityWithHostname:@"www.google.com"] ;//可以以多种形式初始化

    

    [hostReach startNotifier];  //开始监听,会启动一个run loop

    

    return YES;

}

// 连接改变

- (void) reachabilityChanged: (NSNotification* )note

{

    Reachability* curReach = [note object];

    //对连接改变做出响应的处理动作。

    NetworkStatus status = [curReach currentReachabilityStatus];

    if (status == NotReachable) {

        NSLog(@"no net");

    }

    if (status == ReachableViaWiFi) {

        NSLog(@"wifi");

    }

    if (status == ReachableViaWWAN) {

        NSLog(@"wan");

    }

}