Uso da lib connectivity para pegar o IP na rede WIFI do aparelho.

connectivity.dart

import 'package:connectivity/connectivity.dart';
import 'dart:async';
import 'package:flutter/services.dart';

ConnectivityResult result;
    String wifiName, wifiIP;
    
    // Primeiro e necessario verificar a conectividade do aparelho
    try {
      result = await _connectivity.checkConnectivity();
    } on PlatformException catch (e) {
      print(e.toString());
    }
    
    // Executa a logica dependendo do tipo de conexao que o aparelho tem
    if (result == ConnectivityResult.mobile) {
      // I am connected to a mobile network.
      print('to no mobile');
    } else if (result == ConnectivityResult.wifi) {
      // I am connected to a wifi network.
      
      // Pega o nome da rede WIFI
      try {
        wifiName = (await _connectivity.getWifiName()).toString();
      } on PlatformException catch (e) {
        print(e.toString());

        wifiName = "Failed to get Wifi Name";
      }
      
      // Pega o IP do aparelho na rede
      try {
        wifiIP = (await _connectivity.getWifiIP()).toString();
      } on PlatformException catch (e) {
        print(e.toString());

        wifiName = "Failed to get Wifi IP";
      }
    }

    print(wifiName);
    print(wifiIP);