iOS/iPhone可达性 - 如何使用Reachability.m/.h检查互联网何时丢失/无法访问

Question

目前我正在通过apple reachability.m/.h使用该类,它可以工作,除了它通知我任何更改,我想只通知用户网络是否无法访问.目前,如果我有互联网连接,然后松散网络它告诉我.但是当你重新连接到网络时,它也告诉我,我不想要.我希望它只告诉我什么时候有丢失/没有网络.

我认为这与电话有关:

- (void)viewWillAppear:(BOOL)animated
{
    // check for internet connection
    [[NSNotificationCenter defaultCenter]
          addObserver:self
             selector:@selector(checkNetworkStatus:)
                 name:kReachabilityChangedNotification
               object:nil];

    internetReachable = [[Reachability
                         reachabilityForInternetConnection] retain];
    [internetReachable startNotifier];

    // check if a pathway to a random host exists
    hostReachable = [[Reachability reachabilityWithHostName:
                     @"www.google.ca"] retain];
    [hostReachable startNotifier];

    // now patiently wait for the notification
}

在调用时-[NSNotificationCenter addObserver:selector:name:object:],该名称是否具有任何其他功能,然后字面上是一个名称？这是我第一次使用NSNotificationCenter,所以我不太熟悉这个问题.

编辑:

这是我的checkNetworkStatus函数:(问题是我得到"NotReachable",因为网络连接回来了,NSAlert多次关闭)

- (void) checkNetworkStatus:(NSNotification *)notice
{
        // called after network status changes
NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
switch (internetStatus)

{
    case NotReachable:
    {
        UIAlertView * alert  = [[UIAlertView alloc] initWithTitle:@"Network Failed" message:@"Please check your connection and try again." delegate:nil cancelButtonTitle:@"OK" otherButtonTitles:nil ];
        [alert show];
        NSLog(@"The internet is down.");

        break;

    }
    case ReachableViaWiFi:
    {               
        NSLog(@"The internet is working via WIFI.");

        break;

    }
    case ReachableViaWWAN:
    {
        NSLog(@"The internet is working via WWAN.");

        break;

    }
}

NetworkStatus hostStatus = [hostReachable currentReachabilityStatus];
switch (hostStatus)

{
    case NotReachable:
    {
        NSLog(@"A gateway to the host server is down.");

        break;

    }
    case ReachableViaWiFi:
    {
        NSLog(@"A gateway to the host server is working via WIFI.");

        break;

    }
    case ReachableViaWWAN:
    {
        NSLog(@"A gateway to the host server is working via WWAN.");

        break;

    }
}

}

Answer 1

可更改性将在状态发生变化时发送通知,但您对该通知的处理完全取决于您.如果您不想告诉用户网络已恢复,则您不必这样做.

NSNotificationCenter方法中的"name"参数指示您要订阅的通知.当对象发布通知时,它会使用特定名称.