如何在颤振中使配置文件应用栏像电报一样？

如何解决如何在颤振中使配置文件应用栏像电报一样？

由于我是 Flutter 的新手，所以我想要这个动画的完整实现。

解决方法

/// Flutter code sample for SliverAppBar

// This sample shows a [SliverAppBar] and it's behavior when using the
// [pinned],[snap] and [floating] parameters.

import 'package:flutter/material.dart';

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

/// This is the main application widget.
class MyApp extends StatelessWidget {
  static const String _title = 'Flutter Code Sample';

  @override
  Widget build(BuildContext context) {
    return const MaterialApp(
      title: _title,home: MyStatefulWidget(),);
  }
}

/// This is the stateful widget that the main application instantiates.
class MyStatefulWidget extends StatefulWidget {
  const MyStatefulWidget();

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

/// This is the private State class that goes with MyStatefulWidget.
class _MyStatefulWidgetState extends State<MyStatefulWidget> {
  bool _pinned = true;
  bool _snap = false;
  bool _floating = false;

// [SliverAppBar]s are typically used in [CustomScrollView.slivers],which in
// turn can be placed in a [Scaffold.body].
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: CustomScrollView(
        slivers: <Widget>[
          SliverAppBar(
            pinned: _pinned,snap: _snap,floating: _floating,expandedHeight: 160.0,flexibleSpace: const FlexibleSpaceBar(
              title: Text('SliverAppBar'),background: FlutterLogo(),),const SliverToBoxAdapter(
            child: SizedBox(
              height: 20,child: Center(
                child: Text('Scroll to see the SliverAppBar in effect.'),SliverList(
            delegate: SliverChildBuilderDelegate(
              (BuildContext context,int index) {
                return Container(
                  color: index.isOdd ? Colors.white : Colors.black12,height: 100.0,child: Center(
                    child: Text('$index',textScaleFactor: 5),);
              },childCount: 20,],bottomNavigationBar: BottomAppBar(
        child: ButtonBar(
          alignment: MainAxisAlignment.spaceEvenly,children: <Widget>[
            Row(
              children: <Widget>[
                const Text('pinned'),Switch(
                  onChanged: (bool val) {
                    setState(() {
                      _pinned = val;
                    });
                  },value: _pinned,Row(
              children: <Widget>[
                const Text('snap'),Switch(
                  onChanged: (bool val) {
                    setState(() {
                      _snap = val;
                      // Snapping only applies when the app bar is floating.
                      _floating = _floating || _snap;
                    });
                  },value: _snap,Row(
              children: <Widget>[
                const Text('floating'),Switch(
                  onChanged: (bool val) {
                    setState(() {
                      _floating = val;
                      _snap = _snap && _floating;
                    });
                  },value: _floating,);
  }
}

来源 - https://api.flutter.dev/flutter/material/SliverAppBar-class.html