Hibok/lib/home/coin_anim.dart

import 'package:flutter/material.dart';

import '../r.dart';

class CoinAnim extends StatefulWidget {
  @override
  _CoinAnimState createState() => _CoinAnimState();
}

class _CoinAnimState extends State<CoinAnim>
    with SingleTickerProviderStateMixin {
  Animation<double> _animation;
  AnimationController _controller;
  double begin = 100;
  double end = 20;

  @override
  void initState() {
    super.initState();
    // 启动动画controller
    _controller = new AnimationController(
        duration: Duration(milliseconds: 500), vsync: this);
    _controller.addStatusListener((AnimationStatus status) {});

    _animation = new Tween<double>(begin: begin, end: end).animate(_controller)
      ..addListener(() {
        setState(() {});
      });

    _controller.forward(from: begin);
  }

  @override
  void dispose() {
    _controller.stop();
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Positioned(
        child: Container(
            height: _animation.value, child: Image.asset(R.assetsImagesCoin)));
  }
}