ios - 在以下代码中加入3G检测

Question

我有一种检查 Wi-Fi 的方法，这是我从一个旧项目中获得的，现在我需要实际检查 3G 或 < strong>Wifi，如果没有，请给出错误消息。

原始样本工作:

- (BOOL)checkForWIFIConnection {

    Reachability* wifiReach = [Reachability reachabilityForLocalWiFi];
    NetworkStatus netStatus = [wifiReach currentReachabilityStatus];
    if (netStatus!=ReachableViaWiFi)
    {
        UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Sem conexão à internet!", @"AlertView")
                                                            message:NSLocalizedString(@"Não está conectado à internet. Tente novamente após se connectar.", @"AlertView")
                                                           delegate:self
                                                  cancelButtonTitle:NSLocalizedString(@"OK", @"AlertView")
                                                  otherButtonTitles: nil];
        [alertView show];
        return NO;
    }
    else {
        return YES;
    }
}

---

如何让它检查 ReachableViaWWAN ？我可以在这里添加它吗 (<-) ??

- (BOOL)checkForWIFIConnection {

        Reachability* wifiReach = [Reachability reachabilityForLocalWiFi];
        NetworkStatus netStatus = [wifiReach currentReachabilityStatus];
        if (netStatus!=ReachableViaWiFi && ReachableViaWWAN) <- (i get an error saying use of logical && with constant operand)
        {
            UIAlertView *alertView = [[UIAlertView alloc] initWithTitle:NSLocalizedString(@"Sem conexão à internet!", @"AlertView")
                                                                message:NSLocalizedString(@"Não está conectado à internet. Tente novamente após se connectar.", @"AlertView")
                                                               delegate:self
                                                      cancelButtonTitle:NSLocalizedString(@"OK", @"AlertView")
                                                      otherButtonTitles: nil];
            [alertView show];
            return NO;
        }
        else {
            return YES;
        }
    }

感谢您的帮助。

Answer 1

只需更改:

Reachability* wifiReach = [Reachability reachabilityForLocalWiFi];

到:

Reachability* wifiReach = [Reachability reachabilityForInternetConnection];

和

if (netStatus!=ReachableViaWiFi)

到:

if (netStatus == NotReachable)

换句话说:

Reachability* wifiReach = [Reachability reachabilityForInternetConnection];
NetworkStatus netStatus = [wifiReach currentReachabilityStatus];
if (netStatus == NotReachable)
{

顺便说一句 - 请查阅 Objective-C 教程以了解如何编写复合表达式。你的if声明需要是这样的:

if (netStatus!=ReachableViaWiFi && netStatus!=ReachableViaWWAN)

虽然这将解决编译器问题，但它不适用于您的代码，因为 WWAN使用 reachabilityForLocalWiFi 时永远不会给出值.