Flutter -如何向Widget添加动画，以便在按下按钮时滑动到视图中？

import 'package:flutter/material.dart';
import 'package:flutter/animation.dart';

class MyWidget extends StatefulWidget {
  @override
  _MyWidgetState createState() => _MyWidgetState();
}

class _MyWidgetState extends State<MyWidget> with SingleTickerProviderStateMixin {
  AnimationController _controller;
  Animation<Offset> _animation;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(milliseconds: 500),
      vsync: this,
    );
    _animation = Tween<Offset>(
      begin: Offset.zero,
      end: const Offset(0.5, 0.0),
    ).animate(_controller);
  }

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

  @override
  Widget build(BuildContext context) {
    return GestureDetector(
      onTap: () {
        _controller.forward();
      },
      child: SlideTransition(
        position: _animation,
        child: Container(
          width: 200,
          height: 200,
          color: Colors.blue,
        ),
      ),
    );
  }
}

void main() {
  runApp(MaterialApp(
    home: Scaffold(
      body: Center(
        child: MyWidget(),
      ),
    ),
  ));
}