Nilen Patel Inc.

Tutorial and code of Animated AppBar in Flutter. Copy and paste the below code as per your requirements.

appbar_animated: ^0.0.3

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

void main() {
  runApp(const MyApp());
}

class MyApp extends StatelessWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      debugShowCheckedModeBanner: false,
      home: DetailPage(),
    );
  }
}

class DetailPage extends StatelessWidget {
  const DetailPage({
    Key? key,
  }) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ScaffoldLayoutBuilder(
        backgroundColorAppBar:
        const ColorBuilder(Colors.transparent, Colors.blue),
        textColorAppBar: const ColorBuilder(Colors.white),
        appBarBuilder: _appBar,
        child: SingleChildScrollView(
          child: Stack(
            children: [
              Image.network(
                "https://scontent.fstv5-1.fna.fbcdn.net/v/t1.6435-1/103996008_111874850563152_9134752688804599384_n.jpg?stp=dst-jpg_p320x320&_nc_cat=107&ccb=1-5&_nc_sid=1eb0c7&_nc_ohc=2minhGTtP9EAX8BCgpb&_nc_ht=scontent.fstv5-1.fna&oh=00_AT--Ohzzd5xDD48JnMJkRji2UQhlWUMVu8QjRF-VsgOBYw&oe=627B2114",
                width: MediaQuery.of(context).size.width,
                height: MediaQuery.of(context).size.height * 0.4,
                fit: BoxFit.cover,
              ),
              Container(
                margin: EdgeInsets.only(
                  top: MediaQuery.of(context).size.height * 0.36,
                ),
                height: 900,
                decoration: const BoxDecoration(
                  borderRadius: BorderRadius.vertical(
                    top: Radius.circular(40),
                  ),
                  color: Colors.white,
                ),
              ),
            ],
          ),
        ),
      ),
    );
  }

  Widget _appBar(BuildContext context, ColorAnimated colorAnimated) {
    return AppBar(
      backgroundColor: colorAnimated.background,
      elevation: 0,
      title: Center(child: Text(
        "AppBar Animate",
        style: TextStyle(
          color: colorAnimated.color,
        ),
      ),),
    );
  }
}