Unity判断网络连接类型

使用NetworkReachability判断手机游戏当前的网络连接类型，是wifi还是234G

 using UnityEngine;
 using System.Collections;

 public class Test : MonoBehaviour {

     string str;
     // Use this for initialization
     void Start () {
         if (Application.internetReachability == NetworkReachability.ReachableViaCarrierDataNetwork)
         {
             str = "2G/3G/4G";
         }
         else if (Application.internetReachability == NetworkReachability.ReachableViaLocalAreaNetwork)
         {
             str = "wifi";
         }
         else if (Application.internetReachability == NetworkReachability.NotReachable)
         {
             str = "No Network";
         }

     }

     // Update is called once per frame
     void Update () {

     }

     void OnGUI()
     {
         GUILayout.Label(str);
     }
 }