Reachability 类检测网络状态

1、注册通知

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

2、创建Reachability实例对象并开启通知

struct sockaddr_in address;

memset(&address, 0, sizeof(address));

address.sin_len = sizeof(address);

address.sin_family = AF_INET;

address.sin_port = htonl(IP_PORT);

address.sin_addr.s_addr = htons(inet_addr(IP_Address));

reachability = [[Reachability reachabilityWithAddress:&address] retain];

[reachability startNotifier];//开启网络检测

3、网络状态改变接受通知处理

-(void)reachabilityIsChanged:(NSNotification *)notify {

    Reachability *curReach = [notify object];

 

    

    NetworkStatus networkStatus = [curReach currentReachabilityStatus];

    if (networkStatus == NotReachable) { //无网络状态

        //TODO

    } else { //有网络状态，3G或wifi

//TODO

    }

}

4、关闭通知并释放对象

[[NSNotificationCenter defaultCenter] removeObserver:self name:kReachabilityChangedNotification object:nil];

if (reachability) {

    [reachability stopNotifier]; //关闭网络检测

    [reachability release];

}