适用于Android API 21+的VPN的NetworkInfo

Question

我的问题很简单，Android支持以编程方式检查VPN是否处于活动状态（在API 21+上）是指：http://developer.android.com/reference/android/net/ConnectivityManager.html#TYPE_VPN

我以为我知道它应该如何工作但代码（使用roboguice）：

@Inject
    boolean checkVPN(ConnectivityManager connMgr) {
        //don't know why always returns null:
        NetworkInfo networkInfo = connMgr.getNetworkInfo(ConnectivityManager.TYPE_VPN);

        boolean isVpnConn = networkInfo == null ? false : networkInfo.isConnected();
        return isVpnConn;
    }

始终返回null。对于WIFI或MOBILE运作良好。

这是一个错误吗？或者我做错了什么？或者我误解了它应该如何运作？

Answer 1

NetworkCapabilities将致力于API 21+。你必须遍历所有现有的网络并检查哪个有VPN_TRANSPORT

ConnectivityManager cm = (ConnectivityManager)mContext.getSystemService(Context.CONNECTIVITY_SERVICE);
Network[] networks = cm.getAllNetworks();

Log.i(TAG, "Network count: " + networks.length);
for(int i = 0; i < networks.length; i++) {

  NetworkCapabilities caps = cm.getNetworkCapabilities(networks[i]);

  Log.i(TAG, "Network " + i + ": " + networks[i].toString());
  Log.i(TAG, "VPN transport is: " + caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN));
  Log.i(TAG, "NOT_VPN capability is: " + caps.hasCapability(NetworkCapabilities.NET_CAPABILITY_NOT_VPN));

}

Answer 2

如果要检查当前活动的网络是否使用VPN，可以使用：

Network activeNetwork = connectivityManager.getActiveNetwork();
NetworkCapabilities caps = connectivityManager.getNetworkCapabilities(activeNetwork);
boolean vpnInUse = caps.hasTransport(NetworkCapabilities.TRANSPORT_VPN);