gistfile1.cs

    static class ForConnectivityManager
    {
        private const string DebugTag = "YOUR_APP_NAME";
        static IntPtr _connectivityManagerSetMobileDataEnabled;

        public static bool IsMobileDataEnabled(this ConnectivityManager manager)
        {
            var netInfo = manager.GetNetworkInfo(ConnectivityType.Mobile);

            return manager.NetworkStatus() != NetworkState.NoNetwork;
        }

        public static bool Is3GEnabled(this ConnectivityManager manager)
        {
            var networks = manager.GetAllNetworkInfo();

            return (from n in networks where n.TypeName == "mobile_internet" && n.IsConnected select n).Any();
        }

        public static NetworkState NetworkStatus(this ConnectivityManager manager)
        {
            var result = NetworkState.NoNetwork;

            var networks = manager.GetAllNetworkInfo();

            foreach (var network in networks)
            {
                if (network.Type == ConnectivityType.Wifi && network.IsConnected)
                {
                    result = NetworkState.WiFi;
                    break;
                }

                if (network.TypeName == "mobile_internet" && network.IsConnected)
                {
                    result = NetworkState.Mobile;
                    break;
                }
            }

            return result;
        }

        /// <summary>
        /// default timeout = 15 seconds
        /// </summary>
        public static void SetAndWaitForMobileDataEnabled(this ConnectivityManager manager, TelephonyManager telephonyManager, bool value)
        {
            var notConnected = !manager.IsMobileDataEnabled();

            Log.Debug(DebugTag, "Connected to 3G: {0}".With(!notConnected));

            if (notConnected)
            {
                if (_connectivityManagerSetMobileDataEnabled == IntPtr.Zero)
                {
                    _connectivityManagerSetMobileDataEnabled = JNIEnv.GetMethodID(
                        manager.Class.Handle,
                        "setMobileDataEnabled",
                        "(Z)V");
                }

                Log.Debug(DebugTag, "Invoking JNI method: setMobileDataEnabled");

                JNIEnv.CallVoidMethod(
                    manager.Handle,
                    _connectivityManagerSetMobileDataEnabled,
                    new JValue(value));

                var waitCount = 0;
                while (waitCount != 30)
                {
                    Log.Debug(DebugTag, "Waiting 500 milliseconds. WaitCount: {0}".With(waitCount));
                    Thread.Sleep(500);

                    bool isConnected = manager.GetNetworkInfo(ConnectivityType.Mobile).IsConnected;
                    bool istmData = telephonyManager.DataState == DataConnectionStatus.Connected;
                    Log.Debug(DebugTag, "Checking 3g connected: {0}".With(isConnected));

                    if ((isConnected && istmData) == value)
                    {
                        break;
                    }

                    waitCount++;
                }

                Log.Debug(DebugTag, "3g connection toggle complete.");
            }
        }
    }