类似于一个网络状况的探针。

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

    

    hostReach = [[Reachability reachabilityWithHostName: @"hubj.cnblogs.com"] retain];

    [hostReach startNotifier];

    

    wifiReach=[[Reachability reachabilityForLocalWiFi]retain];

    [wifiReach startNotifier];

 

- (void)reachabilityChanged: (NSNotification* )note {

    Reachability* curReach = [note object];

    NSParameterAssert([curReach isKindOfClass: [Reachability class]]);

    

    NetworkStatus netStatus = [curReach currentReachabilityStatus];

    

    switch (netStatus)

    {

        case NotReachable:

        {

            NSLog(@"Access Not Available");

            break;

        }

            

        case ReachableViaWWAN:

        {

            NSLog(@"Reachable WWAN");

            break;

        }

        case ReachableViaWiFi:

        {

            NSLog(@"Reachable WiFi");

            break;

        }

    }

}

 

判断网络是否连接

/*** * 此函数用来判断是否网络连接服务器正常 * 需要导入Reachability类 */ + (BOOL)isExistenceNetwork {
       BOOL isExistenceNetwork;     Reachability *reachability = [Reachability reachabilityWithHostName:@""];  // 测试服务器状态     switch([reachability currentReachabilityStatus]) {
   case NotReachable:                   isExistenceNetwork = FALSE; break; case ReachableViaWWAN:                    isExistenceNetwork = TRUE; break; case ReachableViaWiFi:                     isExistenceNetwork = TRUE; break;      } return  isExistenceNetwork; }

 

实时通知网络状况

/* * 在应用委托的方法didFinishLaunchingWithOptions中添加 */ [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(reachabilityChanged:) name:kReachabilityChangedNotification object:nil]; reachability = [[Reachability reachabilityWithHostName:@"www.baidu.com"] retain]; [reachability startNotifier]; ........ return YES; /** *此函数通过判断联网方式，通知给用户 */ - (void)reachabilityChanged:(NSNotification *)notification {
         Reachability *curReachability = [notification object];       NSParameterAssert([curReachability isKindOfClass:[Reachability class]]);       NetworkStatus curStatus = [curReachability currentReachabilityStatus]; if(curStatus == NotReachable) {
             [DOIN_Util logFax:@"连接失败"];       } }