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Flutter

              
                import 'package:flutter/material.dart';

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

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      home: Scaffold(
        appBar: AppBar(
          title: Text('AnimationController 动画'),
        ),
        body: HeartAnimPage(),
      ),
    );
  }
}

class HeartAnimPage extends StatefulWidget {
  HeartAnimPage({Key key}) : super(key: key);
  @override
  _HeartAnimPageState createState() => _HeartAnimPageState();
}

class _HeartAnimPageState extends State<HeartAnimPage>
    with SingleTickerProviderStateMixin {
  AnimationController controller;
  Animation<double> animation;

  @override
  void initState() {
    super.initState();
    controller =
        AnimationController(vsync: this, duration: Duration(seconds: 1));
    animation = CurvedAnimation(
      parent: controller,
      curve: Curves.elasticInOut,
      reverseCurve: Curves.easeOut,
    );
    animation.addStatusListener((status) {
      if (status == AnimationStatus.completed) {
        controller.reverse();
      } else if (status == AnimationStatus.dismissed) {
        controller.forward();
      }
    });
    animation = Tween(begin: 50.0, end: 120.0).animate(controller);
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Center(
      child: AnimatedBuilder(
        animation: animation,
        builder: (context, child) {
          return Icon(
            Icons.favorite,
            color: Colors.red,
            size: animation.value,
          );
        },
      ),
    );
  }
}


class MyAnimPage extends StatelessWidget {
  final animKey = Key('animKey');
  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(title: Text(' '),),
      body: HeartAnimPage(key: animKey,),
      floatingActionButton: FloatingActionButton(
        child: Icon(Icons.add),
        onPressed: (){
          if(!animKey.currentState.controller.)
        },
      ),

    );
  }
}
              
            
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999px

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