检查网络连接iPhone

Question

我正在开发iPhone应用程序，它是从网站动态获取数据，我正在检查Wifi和GPRS是否连接，但是当WiFi无法连接时，应用程序崩溃。

我正在使用此方法来检查连接。

+ (BOOL) isConnected { 
    // Part 1 - Create Internet socket addr of zero 
    struct sockaddr_in zeroAddr; 
    bzero(&zeroAddr, sizeof(zeroAddr)); 
    zeroAddr.sin_len = sizeof(zeroAddr); 
    zeroAddr.sin_family = AF_INET; 

    // Part 2- Create target in format need by SCNetwork 
    SCNetworkReachabilityRef target = 
    SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *) &zeroAddr); 

    // Part 3 - Get the flags 
    SCNetworkReachabilityFlags flags; 
    SCNetworkReachabilityGetFlags(target, &flags); 

    // Part 4 - Create output 
    NSString *sNetworkReachable; 
    if (flags & kSCNetworkFlagsReachable) 
     sNetworkReachable = @"YES"; 
    else 
     sNetworkReachable = @"NO"; 

    NSString *sCellNetwork; 
    if (flags & kSCNetworkReachabilityFlagsIsWWAN) 
     sCellNetwork = @"YES"; 
    else 
     sCellNetwork = @"NO"; 


    // Get host entry info for given host 
    struct hostent *remoteHostEnt = gethostbyname("google.com"); 
    if(remoteHostEnt == nil) return NO; 

    // Get address info from host entry 
    struct in_addr *remoteInAddr = (struct in_addr *) remoteHostEnt->h_addr_list[0]; 

    // Convert numeric addr to ASCII string 
    char *sRemoteInAddr = inet_ntoa(*remoteInAddr); 

    NSString *s = [[NSString alloc] 
       initWithFormat: 
       @"Network Reachable: %@\n" 
       @"Cell Network: %@\n" 
       @"Remote IP: %s\n", 
       sNetworkReachable, 
       sCellNetwork, 
       sRemoteInAddr]; 


    // Add text 
    [sCellNetwork release]; 
    [sNetworkReachable release]; 

    NSLog(@"Message:%@",s); 

    return [sNetworkReachable isEqualToString:@"YES"]; 
} 

感谢 瓦代夫卢

Answer 1

为什么惹的IP地址？您可以拨打SCNetworkReachabilityCreateWithName()，而不是直接：

SCNetworkReachabilityCreateWithName(kCFAllocatorDefault, "google.com"); 

Answer 2

搜索可达示例应用程序上developer.apple.com

还有GitHub上的开源NPReachability类做同样的事情，但使用块作为处理程序。

Answer 3

您可以使用隐藏的UIWebView并为其加载网站。然后使用UIWebView.h中的方法来检测加载是否成功。