objective-c – 如何检查iPhone应用程序中的网络状态？

在我的viewDidLoad方法中,我调用initNetworkCheck：

[self initNetworkCheck];
[super viewDidLoad];
if(internetActive == NO){     
    compose.enabled = NO;
}

所以我想在启动时检查硬件是否有互联网连接.问题是它总是给我NO,但是当我记录它时,internetActive实际上是YES.

//[[[[[[network check methods
-(void)checkNetworkStatus:(NSNotification *)notice{
    NetworkStatus internetStatus = [internetReachable currentReachabilityStatus];
    switch (internetStatus) {
        case NotReachable:{
            self.internetActive = NO; 
            break;
        }
        case ReachableViaWiFi:{
            self.internetActive = YES;
            break;
        }
        case ReachableViaWWAN:{
            self.internetActive = YES;
            break;
        }
    }
    NetworkStatus hostStatus = [hostReachable currentReachabilityStatus];
    switch (hostStatus){
        case NotReachable:{
            self.hostActive = NO;
            break;
        }
        case ReachableViaWiFi:{
            self.hostActive = YES;
            break;
        }
        case ReachableViaWWAN:{
            self.hostActive = YES;
            break;
        }
    }

}
-(void)initNetworkCheck{
    [[NSNotificationCenter defaultCenter] addObserver:self selector:@selector(checkNetworkStatus:) name:kReachabilityChangedNotification object:nil];

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

    hostReachable = [[Reachability reachabilityWithHostName:@"www.google.com"] retain];
    [hostReachable startNotifier];
}
//]]]]]]

有任何想法吗？