Flutter使您可以借助Overlay类创建通知。 要使这些动画从顶部进入屏幕，可以将SlideTransition 与AnimationController 结合使用。 这是我创建的示例应用程序：

import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(home: Home());
  }
}

class Home extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Center(
        child: RaisedButton.icon(
          icon: Icon(Icons.notifications_active),
          label: Text('Notify!'),
          onPressed: () {
            Navigator.of(context)
                .overlay
                .insert(OverlayEntry(builder: (BuildContext context) {
              return FunkyNotification();
            }));
          },
        ),
      ),
    );
  }
}

class FunkyNotification extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => FunkyNotificationState();
}

class FunkyNotificationState extends State<FunkyNotification>
    with SingleTickerProviderStateMixin {
  AnimationController controller;
  Animation<Offset> position;

  @override
  void initState() {
    super.initState();

    controller =
        AnimationController(vsync: this, duration: Duration(milliseconds: 750));
    position = Tween<Offset>(begin: Offset(0.0, -4.0), end: Offset.zero)
        .animate(
            CurvedAnimation(parent: controller, curve: Curves.bounceInOut));

    controller.forward();
  }

  @override
  Widget build(BuildContext context) {
    return SafeArea(
      child: Material(
        color: Colors.transparent,
        child: Align(
          alignment: Alignment.topCenter,
          child: Padding(
            padding: EdgeInsets.only(top: 32.0),
            child: SlideTransition(
              position: position,
              child: Container(
                decoration: ShapeDecoration(
                    color: Colors.deepPurple,
                    shape: RoundedRectangleBorder(
                        borderRadius: BorderRadius.circular(16.0))),
                child: Padding(
                  padding: EdgeInsets.all(10.0),
                  child: Text(
                    'Notification!',
                    style: TextStyle(
                        color: Colors.white, fontWeight: FontWeight.bold),
                  ),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}