Dark Theme in Flutter

main.dart

import 'package:flutter/material.dart';
import 'package:youtube/Page1.dart';

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

class MyApp extends StatefulWidget {
  MyApp({Key key}) : super(key: key);

  @override
  _MyAppState createState() => _MyAppState();
}

class _MyAppState extends State<MyApp> {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      theme: ThemeData.dark(),
      debugShowCheckedModeBanner: false,
      home: HomePage(),
    );
  }
}

class HomePage extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Scaffold(
      appBar: AppBar(
        title: Text("Dark Theme"),
      ),
      body: SingleChildScrollView(
        child: Column(
          children: <Widget>[
            FlatButton(
              child: Card(
                elevation: 1,
                child: ListTile(
                  trailing: Icon(
                    Icons.navigate_next,
                    size: 40,
                    color: Colors.red,
                  ),
                  title: Text(
                    "My Card",
                    style: TextStyle(
                        fontWeight: FontWeight.normal,
                        fontSize: 25,
                        color: Colors.red),
                  ),
                ),
              ),
              onPressed: () {
                print("hai111");
                Navigator.of(context)
                    .push(MaterialPageRoute(builder: (BuildContext context) {
                  return MyPage1();
                }));
              },
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
            Card(
              elevation: 1,
              child: ListTile(
                trailing: Icon(
                  Icons.navigate_next,
                  size: 40,
                  color: Colors.red,
                ),
                title: Text(
                  "My Card",
                  style: TextStyle(
                      fontWeight: FontWeight.normal,
                      fontSize: 25,
                      color: Colors.red),
                ),
              ),
            ),
          ],
        ),
      ),
    );
  }
}

Page1.dart

import 'package:flutter/material.dart';

class MyPage1 extends StatefulWidget {
  MyPage1({Key key}) : super(key: key);

  @override
  My_Page1State createState() => My_Page1State();
}

class My_Page1State extends State<MyPage1> {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: Text("Welcome", style: TextStyle(fontSize: 30)),
      ),
    );
  }
}