Flutter- How to change the color of my app bar with search function add to it?

Question

I am trying to change the color of my app bar my I am not getting an option to change it. As I am following a tutorial video they have not shown to edit the color. please help!

import 'package:flutter/material.dart';



class SearchList extends StatefulWidget {
  SearchList({ Key key }) : super(key: key);
  @override
  SearchListState createState() => new SearchListState();

}

class SearchListState extends State<SearchList>
{

  Widget appBarTitle = new Text("Search Product..", style: new TextStyle(color: Colors.white),);
  Icon actionIcon = new Icon(Icons.search, color: Colors.white);
  final key = new GlobalKey<ScaffoldState>();
  final TextEditingController searchQuery = new TextEditingController();
  List<String> _list;
  bool issearching;
  String _searchText = "";

  SearchListState() {
    searchQuery.addListener(() {
      if (searchQuery.text.isEmpty) {
        setState(() {
          issearching = false;
          _searchText = "";
        });
      }
      else {
        setState(() {
          issearching = true;
          _searchText = searchQuery.text;
        });
      }
    });
  }

  @override
  void initState() {
    super.initState();
    issearching = false;
    init();

  }

  void init() {
    _list = List();
    _list.add("shirts");
    _list.add("shoes");
    _list.add("jeans");
    _list.add("informals");
    _list.add("formals");
    _list.add("dresses");
    _list.add("accessories");

  }

  @override
  Widget build(BuildContext context) {
    return new Scaffold(
      key: key,
      appBar:

         buildBar(context),



       body: new ListView(
        padding: new EdgeInsets.symmetric(vertical: 8.0),
        children: issearching ? _buildSearchList() : _buildList(),
      ),
    );

  }

  List<ChildItem> _buildList() {
    return _list.map((contact) => new ChildItem(contact)).toList();
  }

  List<ChildItem> _buildSearchList() {
    if (_searchText.isEmpty) {
      return _list.map((contact) => new ChildItem(contact))
          .toList();
    }
    else {
      List<String> _searchList = List();
      for (int i = 0; i < _list.length; i++) {
        String  name = _list.elementAt(i);
        if (name.toLowerCase().contains(_searchText.toLowerCase())) {
          _searchList.add(name);
        }
      }
      return _searchList.map((contact) => new ChildItem(contact))
          .toList();
    }
  }

  Widget buildBar(BuildContext context) {
    return new AppBar(
        centerTitle: true,
        title: appBarTitle,
        actions: <Widget>[
          new IconButton(icon: actionIcon, onPressed: () {
            setState(() {
              if (this.actionIcon.icon == Icons.search) {
                this.actionIcon = new Icon(Icons.close, color: Colors.white,);
                this.appBarTitle = new TextField(
                  controller: searchQuery,
                  style: new TextStyle(
                    color: Colors.white,

                  ),
                  decoration: new InputDecoration(
                      prefixIcon: new Icon(Icons.search, color: Colors.white),
                      hintText: "Search...",
                      hintStyle: new TextStyle(color: Colors.white)
                  ),
                );
                _handleSearchStart();
              }
              else {
                _handleSearchEnd();
              }
            });
          },),
        ]
    );
  }

  void _handleSearchStart() {
    setState(() {
      issearching = true;
    });
  }

  void _handleSearchEnd() {
    setState(() {
      this.actionIcon = new Icon(Icons.search, color: Colors.white,);
      this.appBarTitle =
      new Text("Search Sample", style: new TextStyle(color: Colors.white),);
      issearching = false;
      searchQuery.clear();
    });
  }

}

class ChildItem extends StatelessWidget {
  final String name;
  ChildItem(this.name);
  @override
  Widget build(BuildContext context) {
    return new ListTile(title: new Text(this.name));
  }

}

I wanted a green accent color on my appBar but I am getting the default blue of flutter. I can't seem to find the right location to put the themeData of my appBar. Any help would be appreciated. Thanks. What I want as a result

What I am getting

Answer 1

After a reading through tons of documentation, I finally found the answer.

Note: This is the solution if you are using a SearchDelegate to show your search screen.

Inside your SearchDelegate subclass, override appBarTheme

@override
ThemeData appBarTheme(BuildContext context) {
    return Theme.of(context);
}

By default, the class sets the background as white, so you just gotta change it to this to be able to see your theme's colors.

Hope this helps.