虽然有一个正确的答案，我在这里分享我的答案，希望这样会更方便。

WifiManager wifiMan = (WifiManager) context.getSystemService(Context.WIFI_SERVICE);
WifiInfo wifiInf = wifiMan.getConnectionInfo();
int ipAddress = wifiInf.getIpAddress();
String ip = String.format("%d.%d.%d.%d", (ipAddress & 0xff),(ipAddress >> 8 & 0xff),(ipAddress >> 16 & 0xff),(ipAddress >> 24 & 0xff));

引用 // get设备Ip地址

open fun getLocalIpAddress(): String? {
    try {
        val en: Enumeration<NetworkInterface> = NetworkInterface.getNetworkInterfaces()
        while (en.hasMoreElements()) {
            val networkInterface: NetworkInterface = en.nextElement()
            val enumerationIpAddress: Enumeration<InetAddress> = networkInterface.inetAddresses
            while (enumerationIpAddress.hasMoreElements()) {
                val inetAddress: InetAddress = enumerationIpAddress.nextElement()
                if (!inetAddress.isLoopbackAddress && inetAddress is Inet4Address) {
                    return inetAddress.getHostAddress()
                }
            }
        }
    } catch (ex: SocketException) {
        ex.printStackTrace()
    }
    return null
}

下面的代码可能会帮助你..不要忘记添加权限..

public String getLocalIpAddress(){
   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()) {
                return inetAddress.getHostAddress();
                }
           }
       }
       } catch (Exception ex) {
          Log.e("IP Address", ex.toString());
      }
      return null;
}

在清单文件中添加以下权限。

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

编码快乐! !

private InetAddress getLocalAddress()throws IOException {

            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()) {
                            //return inetAddress.getHostAddress().toString();
                            return inetAddress;
                        }
                    }
                }
            } catch (SocketException ex) {
                Log.e("SALMAN", ex.toString());
            }
            return null;
        }

WifiManager wm = (WifiManager) getSystemService(WIFI_SERVICE);
String ipAddress = BigInteger.valueOf(wm.getDhcpInfo().netmask).toString();

我不使用Android，但我会用完全不同的方式来解决这个问题。

发送一个查询到谷歌，像这样: https://www.google.com/webhp?sourceid=chrome-instant&ion=1&espv=2&ie=UTF-8#q=my%20ip

并引用发布响应的HTML字段。您也可以直接查询到源。

谷歌最可能比你的应用程序存在的时间长。

只要记住，这可能是你的用户在这个时候没有互联网，你希望发生什么!

祝你好运