Reachablity检测网络状态 包含代码

检测网络状态的代码，使用block的形式：

    Reachability * reach = [Reachability reachabilityWithHostname:@"www.google.com"];    reach.reachableBlock = ^(Reachability * reachability)    {        dispatch_async(dispatch_get_main_queue(), ^{            blockLabel.text = @"Block Says Reachable";        });    };    reach.unreachableBlock = ^(Reachability * reachability)    {        dispatch_async(dispatch_get_main_queue(), ^{            blockLabel.text = @"Block Says Unreachable";        });    };    [reach startNotifier];

?

使用通知的形式：

- (void)viewDidLoad{    [[NSNotificationCenter defaultCenter] addObserver:self                                              selector:@selector(reachabilityChanged:)                                                  name:kReachabilityChangedNotification                                                object:nil];}-(void)reachabilityChanged:(NSNotification*)note{    Reachability * reach = [note object];        if([reach isReachable])    {        notificationLabel.text = @"Notification Says Reachable";    }    else    {        notificationLabel.text = @"Notification Says Unreachable";    }}

?