Question

当我开始使用iPhone调试手机以测试我正在制作的应用程序时，它始终不返回任何网络连接，我知道我有一个。设置正确。

我对此很陌生，请保持温柔。

在下面的代码中， if (defaultNetworkAvailable && ((flags & NetworkReachabilityFlags.IsDirect) != 0)) 总是返回false。

{
    public class NetworkConnection :INetworkConnection
    {
        public bool IsConnected { get; set; }

        public void CheckNetworkConnection()
        {
            InternetStatus();
        }

        public bool InternetStatus()
        {
            NetworkReachabilityFlags flags;
            bool defaultNetworkAvailable = IsNetworkAvailable(out flags);

            if (defaultNetworkAvailable && ((flags & NetworkReachabilityFlags.IsDirect) != 0))
            {
                return false;
            }
            else if ((flags & NetworkReachabilityFlags.IsWWAN) != 0)
            {
                return true;
            }
            else if (flags == 0)
            {
                return false;
            }
            return true;
        }

        private event EventHandler ReachabilityChanged;
        private void OnChange(NetworkReachabilityFlags flags)
        {
            var h = ReachabilityChanged;
            if(h != null)
            {
                h(null, EventArgs.Empty);
            }
        }

        private NetworkReachability defaultReachability;
        public bool IsNetworkAvailable(out NetworkReachabilityFlags flags)
        {
            if(defaultReachability == null)
            {
                defaultReachability = new NetworkReachability(new System.Net.IPAddress(0));
                defaultReachability.SetNotification(OnChange);
                defaultReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
            }
            if(!defaultReachability.TryGetFlags(out flags))
            {
                return false;
            }
            return IsReachableWithoutRequiringConnection(flags);
        }

        private bool IsReachableWithoutRequiringConnection(NetworkReachabilityFlags flags)
        {
            bool isReachable = (flags & NetworkReachabilityFlags.Reachable) != 0;
            bool noConnectionRequired = (flags & NetworkReachabilityFlags.ConnectionRequired) == 0;

            if ((flags & NetworkReachabilityFlags.IsWWAN) != 0)
                noConnectionRequired = true;
            return isReachable && noConnectionRequired;
        }
    }
}

Answer 1

要找出为什么if (defaultNetworkAvailable && ((flags & NetworkReachabilityFlags.IsDirect) != 0))总是返回false的原因。您可以一边打印defaultNetworkAvailable和flags来找出问题所在。

运行代码时，我得到：

defaultNetworkAvailable = true;
flags = NetworkReachabilityFlags.Reachable;

因此，它并没有向我返回false。

以下是networkreachabilityflags的文档。

此外，我建议您使用xamarin/essentials/connectivity测试Netconnection。更简单。

using Xamarin.Essentials;
var current = Connectivity.NetworkAccess;

if (current == NetworkAccess.Internet)
{
    // Connection to internet is available
}

document是有关Xamarin.Essentials的使用方法。

Answer 2

如果您只是想检查Internet访问，则可以使用简单的帮助程序而无需任何插件。

    internal static bool IsInternetAvailable()
    {
        try
        {
            Ping myPing = new Ping();
            String host = "google.com";
            byte[] buffer = new byte[32];
            int timeout = 4000;
            PingOptions pingOptions = new PingOptions();
            PingReply reply = myPing.Send(host, timeout, buffer, pingOptions);
            return true;
        }
        catch (Exception)
        {
            return false;
        }

    }

测试中无法获得网络连接

2 个答案: