flutter 打開應用的閃屏動畫

import 'package:flutter/material.dart';
import 'package:flutter_app/pages/SplashScreen.dart';



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

class MyApp extends StatelessWidget {

  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.green,  //定義主題風格    primarySwatch
      ),
      home:  SplashScreen(),
    );
  }

}

import 'package:flutter/material.dart';

import '../MyHomePage.dart';


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

class _SplashScreenState extends State<SplashScreen> with SingleTickerProviderStateMixin {

  AnimationController _controller;
  Animation _animation;

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


    /*動畫事件監聽器，
    它可以監聽到動畫的執行狀態，
    我們這里只監聽動畫是否結束，
    如果結束則執行頁面跳轉動作。 */
    _animation.addStatusListener((status){
      if(status == AnimationStatus.completed){
        Navigator.of(context).pushAndRemoveUntil(
            MaterialPageRoute(builder: (context)=>MyHomePage()),
                (route)=> route==null);
      }
    });
    //播放動畫
    _controller.forward();
  }

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


  @override
  Widget build(BuildContext context) {
    return FadeTransition( //透明度動畫組件
      opacity: _animation,  //執行動畫
      child: Image.network(  //網絡圖片
          'https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1546851657199&di=fdd278c2029f7826790191d59279dbbe&imgtype=0&src=http%3A%2F%2Fimg.zcool.cn%2Fcommunity%2F0112cb554438090000019ae93094f1.jpg%401280w_1l_2o_100sh.jpg',
          scale: 2.0,  //進行縮放
          fit:BoxFit.cover  // 充滿父容器
      ),
    );
  }
}