flutter 动画

1. App闪屏动画（应用进入界面广告）案例：

import 'package:flutter/material.dart';
import 'home_page.dart';    // MyHomePage()

class SplashScreen extends StatefulWidget {
  @override
  _SplashScreenState createState() => _SplashScreenState();
}

// 混入
class _SplashScreenState extends State<SplashScreen>
    with SingleTickerProviderStateMixin {
  // 动画控制器
  AnimationController _container;
  Animation _animation;

  @override
  void initState() {
    super.initState();
    _container = AnimationController(
        vsync: this, duration: Duration(milliseconds: 3000));
    _animation = Tween(begin: 0.0, end: 1.0).animate(_container);

    _animation.addStatusListener((status) {
      if (status == AnimationStatus.completed) {
        Navigator.of(context).pushAndRemoveUntil(
          MaterialPageRoute(builder: (cintext) => MyHomePage()), // 显示完后跳转到首页
          (route) => route == null,
        );
      }
    });

    _container.forward(); // 播放动画
  }

  @override
  void dispose() {
    _container.dispose(); // 销毁控制器
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return FadeTransition(
      opacity: _animation,
      child: Image.network(
        'http://hbimg.b0.upaiyun.com/615efb61cbc8ec8aad8febdf5a74541fb79c54862658a-mPdqeZ_fw658',
        scale: 2.0,
        fit: BoxFit.cover,
      ),
    );
  }
}