How To Use Stream Builder With Dropdown Using Flutter App

import 'dart:async';
import 'package:flutter/material.dart';

void main() => runApp(new MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      debugShowCheckedModeBanner: false,
      home: MyHomePage(),
    );
  }
}
class MyHomePage extends StatefulWidget {
  final String title;
  MyHomePage({this.title});
  @override
  _MyHomePageState createState() => _MyHomePageState();
}
class _MyHomePageState extends State<MyHomePage> {
  Stream<int> timedCounter(Duration interval, [int maxCount]) async* {
    int i = 0;
    while (true) {
      await Future.delayed(interval);
      yield i++;
      if (i == maxCount) break;
    }
  }
  Widget _buildDropwDown(int count) {
    List<DropdownButton> dropdowns = List.generate(count, (i) {
      return DropdownButton<int>(
        items: [
          DropdownMenuItem<int>(
            child: Text("Flutter"),
            value: 1,
          ),
          DropdownMenuItem<int>(
            child: Text("Android"),
            value: 2,
          ),
          DropdownMenuItem<int>(
            child: Text("Dart"),
            value: 3,
          ),
          DropdownMenuItem<int>(
            child: Text("Ios"),
            value: 4,
          ),
        ],
        isExpanded: false,
        onChanged: (int val) {},
        hint: Text('Select Website'),
      );
    });
    return ListView(
      children: dropdowns,
    );
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        backgroundColor: Colors.pink[700],
          title: Text("Stream Builder With Dropdown")),
      body: StreamBuilder<int>(
        stream: timedCounter(Duration(seconds: 2), 10),
        builder: (context, snapshot) {
          if (!snapshot.hasData) {
            return Text("No data");
          }
          return _buildDropwDown(snapshot.data);
        },
      ),
    );
  }
}