最近，一个IP地址仍然由getLocalIpAddress()返回，尽管与网络断开连接(没有服务指示器)。说明“设置>关于话机>状态”中显示的IP地址与应用程序想象的不一致。

我之前已经通过添加以下代码实现了一个解决方案:

ConnectivityManager cm = getConnectivityManager();
NetworkInfo net = cm.getActiveNetworkInfo();
if ((null == net) || !net.isConnectedOrConnecting()) {
    return null;
}

有谁听过吗?

在AndroidManifest.xml中声明ACCESS_WIFI_STATE权限:

<uses-permission
    android:name="android.permission.ACCESS_WIFI_STATE"/>

可以通过WifiManager获取IP地址:

Context context = requireContext().getApplicationContext();
WifiManager wm = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
String ip = Formatter.formatIpAddress(wm.getConnectionInfo().getIpAddress());

老实说，我对代码安全只是有点熟悉，所以这可能有点像黑客。但对我来说，这是最通用的方法:

package com.my_objects.ip;

import java.net.InetAddress;
import java.net.UnknownHostException;

public class MyIpByHost 
{
  public static void main(String a[])
  {
   try 
    {
      InetAddress host = InetAddress.getByName("nameOfDevice or webAddress");
      System.out.println(host.getHostAddress());
    } 
   catch (UnknownHostException e) 
    {
      e.printStackTrace();
    }
} }

public static String getdeviceIpAddress() {
    try {
        for (Enumeration<NetworkInterface> en = NetworkInterface.getNetworkInterfaces(); en.hasMoreElements();) {
            NetworkInterface intf = en.nextElement();
            for (Enumeration<InetAddress> enumIpAddr = intf.getInetAddresses(); enumIpAddr.hasMoreElements();) {
                InetAddress inetAddress = enumIpAddr.nextElement();
                if (!inetAddress.isLoopbackAddress() && inetAddress instanceof Inet4Address) {
                    return inetAddress.getHostAddress();
                }
            }
        }
    } catch (SocketException ex) {
        ex.printStackTrace();
    }
    return null;
}

编译一些想法，以更好的kotlin解决方案从WifiManager获得wifi ip:

private fun getWifiIp(context: Context): String? {
  return context.getSystemService<WifiManager>().let {
     when {
      it == null -> "No wifi available"
      !it.isWifiEnabled -> "Wifi is disabled"
      it.connectionInfo == null -> "Wifi not connected"
      else -> {
        val ip = it.connectionInfo.ipAddress
        ((ip and 0xFF).toString() + "." + (ip shr 8 and 0xFF) + "." + (ip shr 16 and 0xFF) + "." + (ip shr 24 and 0xFF))
      }
    }
  }
}

或者，您可以通过NetworkInterface获取ip4环回设备的ip地址:

fun getNetworkIp4LoopbackIps(): Map<String, String> = try {
  NetworkInterface.getNetworkInterfaces()
    .asSequence()
    .associate { it.displayName to it.ip4LoopbackIps() }
    .filterValues { it.isNotEmpty() }
} catch (ex: Exception) {
  emptyMap()
}

private fun NetworkInterface.ip4LoopbackIps() =
  inetAddresses.asSequence()
    .filter { !it.isLoopbackAddress && it is Inet4Address }
    .map { it.hostAddress }
    .filter { it.isNotEmpty() }
    .joinToString()

简单地使用凌空从这个网站获得ip

RequestQueue queue = Volley.newRequestQueue(this);    
String urlip = "http://checkip.amazonaws.com/";

    StringRequest stringRequest = new StringRequest(Request.Method.GET, urlip, new Response.Listener<String>() {
        @Override
        public void onResponse(String response) {
            txtIP.setText(response);

        }
    }, new Response.ErrorListener() {
        @Override
        public void onErrorResponse(VolleyError error) {
            txtIP.setText("didnt work");
        }
    });

    queue.add(stringRequest);