这对我有用: 从API 16到23进行了测试:

This is works for me: Tested from API 16 to 23:

List<String> networkList = new ArrayList<>();
try {
    for (NetworkInterface networkInterface : Collections.list(NetworkInterface.getNetworkInterfaces())) {
        if (networkInterface.isUp())
            networkList.add(networkInterface.getName());
    }
} catch (Exception ex) {
    Timber.d("isVpnUsing Network List didn't received");
}

return networkList.contains("tun0");

P.S.也可以是另一个名为"ppp0"的networkInterface，但是在我对不同VPN应用程序的测试中，它始终是"tun0"

P.S. Also it can be another networkInterface with name "ppp0", but in my tests with different VPN apps it's always was "tun0"