C# NetworkReachability类代码示例

 /// <summary>
 /// Initializes a new instance of the <see cref="Reachability.Reachability"/> class.
 /// </summary>
 /// <param name='reachability'>
 /// NetworkReachability instance to use
 /// </param>
 /// <param name='hasWWAN'>
 /// Platform has a WWAN interface
 /// </param>
 protected Reachability(NetworkReachability reachability, bool hasWWAN)
 {
     NetworkReachability = reachability;
     HasWWAN = hasWWAN;
     AllowWWAN = true;
     NetworkReachability.SetNotification(OnReachabilityNotification);
     NetworkReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
 }

        static NetworkInformation()
        {
#if __ANDROID__
            _manager = ConnectivityManager.FromContext(Plugin.CurrentActivity.CrossCurrentActivity.Current.Activity);
            //_manager = ConnectivityManager.FromContext(InTheHand.Platform.Android.ContextManager.Context);
#elif __IOS__ || __TVOS__
            _reachability = new NetworkReachability("0.0.0.0");
#endif
        }

		static bool IsNetworkAvailable(out NetworkReachabilityFlags flags)
		{
			if (defaultRouteReachability == null) {
				defaultRouteReachability = new NetworkReachability(new IPAddress(0));
				defaultRouteReachability.SetNotification(OnChange);
				defaultRouteReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
			}
			return defaultRouteReachability.TryGetFlags(out flags) && IsReachableWithoutRequiringConnection(flags);
		}

 public static ENetworkDataType ConvertDataType(NetworkReachability type)
 {
     //return ENetworkDataType.MobileData;
     return type == NetworkReachability.NotReachable ?
         ENetworkDataType.None :
         type == NetworkReachability.ReachableViaCarrierDataNetwork ?
         ENetworkDataType.MobileData :
         ENetworkDataType.Cable;
 }

		public static bool IsAdHocWiFiNetworkAvailable (out NetworkReachabilityFlags flags)
		{
			if (adHocWiFiNetworkReachability == null) {
				adHocWiFiNetworkReachability = new NetworkReachability(new IPAddress(new byte [] { 169, 254, 0, 0 }));
				adHocWiFiNetworkReachability.SetNotification(OnChange);
				adHocWiFiNetworkReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
			}

			return adHocWiFiNetworkReachability.TryGetFlags(out flags) && IsReachableWithoutRequiringConnection(flags);
		}

		// Is the host reachable with the current network configuration
		public static bool IsHostReachable(string host)
		{
			if (string.IsNullOrEmpty(host))
				return false;

			using (var r = new NetworkReachability(host)) {
				NetworkReachabilityFlags flags;

				if (r.TryGetFlags(out flags))
					return IsReachableWithoutRequiringConnection(flags);
			}
			return false;
		}

    //
    // Returns true if it is possible to reach the AdHoc WiFi network
    // and optionally provides extra network reachability flags as the
    // out parameter
    //
    public static bool IsAdHocWiFiNetworkAvailable(out NetworkReachabilityFlags flags)
    {
        if (_adHocWiFiNetworkReachability == null) {
            _adHocWiFiNetworkReachability = new NetworkReachability (new IPAddress (new byte[] { 169, 254, 0, 0 }));
            _adHocWiFiNetworkReachability.SetCallback (OnChange);
            _adHocWiFiNetworkReachability.Schedule (CFRunLoop.Current, CFRunLoop.ModeDefault);
        }

        if (!_adHocWiFiNetworkReachability.TryGetFlags (out flags))
            return false;

        return IsReachableWithoutRequiringConnection (flags);
    }

		void InitializeReachability ()
		{
			networkReachability = new NetworkReachability (IPAddress.Any);
			networkReachability.SetNotification (flags => UpdateReachability (flags, NetworkIcon, NetworkStatusTextField));
			networkReachability.Schedule ();

			NetworkReachabilityFlags networkReachabilityFlags;
			networkReachability.TryGetFlags (out networkReachabilityFlags);
			UpdateReachability (networkReachabilityFlags, NetworkIcon, NetworkStatusTextField);

			CreateHostReachability ();

			HostTextField.Changed += (sender, e) => CreateHostReachability ();
		}

		// Is the host reachable with the current network configuration
		public static bool IsHostReachable (string host)
		{
			if (host == null || host.Length == 0)
				return false;
	
			using (var r = new NetworkReachability (host)){
				NetworkReachabilityFlags flags;
	
				if (r.TryGetFlags (out flags)){
					return IsReachableWithoutRequiringConnection (flags);
				}
			}
			return false;
		}

        public static bool IsAdHocWiFiNetworkAvailable(out NetworkReachabilityFlags flags)
        {
            if (adHocWiFiNetworkReachability == null)
            {
                adHocWiFiNetworkReachability = new NetworkReachability(new IPAddress(new byte[] {169, 254, 0, 0}));
#warning Need to look at SetNotification instead - ios6 change
                adHocWiFiNetworkReachability.SetNotification(OnChange);
                adHocWiFiNetworkReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
            }

            if (!adHocWiFiNetworkReachability.TryGetFlags(out flags))
                return false;

            return IsReachableWithoutRequiringConnection(flags);
        }

    public override bool FinishedLaunching(UIApplication app, NSDictionary options)
    {
        imageCarrier = UIImage.FromFile ("WWAN5.png");
        imageWiFi = UIImage.FromFile ("Airport.png");
        imageStop = UIImage.FromFile ("stop-32.png");

        nr = new NetworkReachability ("www.apple.com");
        nr.SetCallback (ReachabilityChanged);
        nr.Schedule (CFRunLoop.Current, CFRunLoop.ModeDefault);

        AddTable ();
        //UpdateStatus ();
        //UpdateCarrierWarning ();

        window.MakeKeyAndVisible ();

        return true;
    }

		/// <summary>
		/// Checks if host is reachable
		/// </summary>
		/// <param name="host"></param>
		/// <param name="port"></param>
		/// <returns></returns>
		public static bool IsHostReachable (string host, int port)
		{
			if (string.IsNullOrWhiteSpace (host))
				return false;

			IPAddress address;
			if (!IPAddress.TryParse (host + ":" + port, out address)) {
				Debug.WriteLine (host + ":" + port + " is not valid");
				return false;
			}
			using (var r = new NetworkReachability (host)) {

				NetworkReachabilityFlags flags;

				if (r.TryGetFlags (out flags)) {
					return IsReachableWithoutRequiringConnection (flags);
				}
			}
			return false;
		}

		void CreateHostReachability ()
		{
			if (hostReachability != null) {
				hostReachability.Unschedule ();
				hostReachability.Dispose ();
			}

			if (String.IsNullOrEmpty (HostTextField.StringValue)) {
				HostIcon.Image = NSImage.ImageNamed ("disconnected");
				HostStatusTextField.StringValue = "Enter a host name or IP address";
				return;
			}

			hostReachability = new NetworkReachability (HostTextField.StringValue);
			hostReachability.SetNotification (flags => UpdateReachability (flags, HostIcon, HostStatusTextField));
			hostReachability.Schedule ();

			NetworkReachabilityFlags networkReachabilityFlags;
			networkReachability.TryGetFlags (out networkReachabilityFlags);
			UpdateReachability (networkReachabilityFlags, NetworkIcon, NetworkStatusTextField);
		}

		public void CreateConnectivityWatchDog (Action<bool> connectivityChanged)
		{
			this.connectivityChanged = connectivityChanged;

			if (remoteHostReachability == null)
			{
				if (remoteHostReachability != null)
				{
					remoteHostReachability.Unschedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
				}

				// Create new instance if host address changed.
				remoteHostReachability = new NetworkReachability(new System.Net.IPAddress(0));
				remoteHostReachability.SetNotification(HandleReachabilityChanged);
				remoteHostReachability.Schedule(CFRunLoop.Current, CFRunLoop.ModeDefault);
			}

			// Trigger callback.
			if (this.connectivityChanged != null)
			{
				this.connectivityChanged (true);
			}
		}

        static bool IsNetworkAvailable(out NetworkReachabilityFlags flags)
        {

            if (defaultRouteReachability == null)
            {
                var data = new byte[] { 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 255, 255, 0, 0, 0, 0 };
                var ip = new IPAddress(data, 0);
                defaultRouteReachability = new NetworkReachability(ip);
                defaultRouteReachability.SetNotification(OnChange);
                defaultRouteReachability.Schedule(CFRunLoop.Main, CFRunLoop.ModeDefault);
            }
            if (!defaultRouteReachability.TryGetFlags(out flags))
                return false;
            return IsReachableWithoutRequiringConnection(flags);
        }