ios检查网络状态

+ (BOOL) connectedToNetwork

{

    // 创建零地址，0.0.0.0地址表示查询本机的网络连接状态

    struct sockaddr_in zeroAddress;

    bzero(&zeroAddress, sizeof(zeroAddress));

    zeroAddress.sin_len = sizeof(zeroAddress);

    zeroAddress.sin_family = AF_INET;

    // Recover reachability flags

    SCNetworkReachabilityRef defaultRouteReachability = SCNetworkReachabilityCreateWithAddress(NULL, (struct sockaddr *)&zeroAddress);

    SCNetworkReachabilityFlags flags;

    // Get connect flags

    BOOL didRetrieveFlags = SCNetworkReachabilityGetFlags(defaultRouteReachability, &flags);

    CFRelease(defaultRouteReachability);

    // 如果不能获取连接标志，则不能连接网络，直接返回

    if (!didRetrieveFlags)

    {

         return NO;

    }

 

    // 根据获得的连接标志进行判断

    BOOL isReachable = flag & kSCNetworkFlagsReachable;

    BOOL needsConnection = flags & kSCNetworkFlagsConnectionRequired;

 

    return (isReachable && !needsConnection) ? YES : NO;

}