实现flutter 漂亮加载动画的例子

以下是一个漂亮的 Flutter 加载动画的示例，包含了多种不同类型的加载动画，你可以参考实现自己的加载动画。

import 'package:flutter/material.dart';

class BeautifulLoadingAnimation extends StatefulWidget {
  @override
  _BeautifulLoadingAnimationState createState() => _BeautifulLoadingAnimationState();
}

class _BeautifulLoadingAnimationState extends State<BeautifulLoadingAnimation>
    with SingleTickerProviderStateMixin {
  AnimationController _controller;
  Animation<Color> _colorTween;

  @override
  void initState() {
    super.initState();
    _controller = AnimationController(
      duration: const Duration(milliseconds: 2000),
      vsync: this,
    )..repeat();
    _colorTween = _controller.drive(ColorTween(
      begin: Colors.red,
      end: Colors.blue,
    ));
  }

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text('Beautiful Loading Animation'),
      ),
      body: Center(
        child: Column(
          mainAxisAlignment: MainAxisAlignment.center,
          children: [
            CircularProgressIndicator(
              valueColor: _colorTween,
            ),
            SizedBox(height: 20),
            LinearProgressIndicator(
              valueColor: _colorTween,
            ),
            SizedBox(height: 20),
            Stack(
              alignment: Alignment.center,
              children: [
                CircularProgressIndicator(
                  valueColor: _colorTween,
                ),
                Text(
                  'Loading',
                  style: TextStyle(
                    color: Colors.black,
                    fontSize: 20,
                  ),
                ),
              ],
            ),
            SizedBox(height: 20),
            Container(
              width: 100,
              height: 100,
              child: CircularProgressIndicator(
                strokeWidth: 10,
                valueColor: _colorTween,
              ),
            ),
            SizedBox(height: 20),
            CupertinoActivityIndicator(
              radius: 20,
            ),
          ],
        ),
      ),
    );
  }
}

运行该示例可以看到多种不同类型的加载动画效果。