How to do it...

In this recipe, we will use a FadeTransition into an AnimatedList:

1. Create a new file in the lib folder, called animatedlist.dart.
2. At the top of the file, import material.dart:

import 'package:flutter/material.dart';

3. Create a stateful widget, calling it AnimatedListScreen:

class AnimatedListScreen extends StatefulWidget {
  @override
  _AnimatedListScreenState createState() =>
   _AnimatedListScreenState();
  }
class _AnimatedListScreenState extends State<AnimatedListScreen> {
  @override
  Widget build(BuildContext context) {
    return Container();
  }
}

4. At the top of the _AnimatedListScreenState class, declare a GlobalKey that you will use to access the AnimatedList from anywhere within the class:

final GlobalKey<AnimatedListState> listKey = GlobalKey<AnimatedListState>();

5. Under the GlobalKey, declare a List of int values, and set the list to contain numbers from 1 to 5, and a counter integer:

final List<int> _items ...