Flutter类似于电力输送的动画

利用flutter写了个类似于充电的动画，比如光伏板给电池充电，模仿电力输送的过程，效果如下图所示

下面直接贴出代码，属性都标注了注释，使用的时候在外面加个盒子固定宽高，然后给出每个点的坐标，内部会根据坐标的点数来判断有几根线，然后画出线的路径，进行动画模拟，可以根据项目需求来自定义点的颜色，每条路径上点的个数以及点的大小等等，

复制代码

import 'package:flutter/material.dart';

class ElectricAnimated extends StatelessWidget {
  final int duration; //动画时长
  final List<Offset> path; //路径的点坐标
  const ElectricAnimated({
    super.key,
    this.duration = 5,
    required this.path,
  });

  @override
  Widget build(BuildContext context) {
    return Stack(
      children: List.generate(
        path.length - 1,
        (index) {
          return AnimatedDots(
            path: [
              path[index],
              path[index + 1],
            ],
            dotCount: 3,
            duration: Duration(
              seconds: duration,
            ),
          );
        },
      ),
    );
  }
}

class AnimatedDots extends StatefulWidget {
  final List<Offset> path; //路径的点坐标
  final int dotCount; //每条路径上的点的个数
  final double dotSize; //点的大小
  final Duration duration;
  final Color dotColor; //点的颜色

  const AnimatedDots({
    Key? key,
    required this.path,
    this.dotCount = 5,
    this.dotSize = 2,
    this.duration = const Duration(seconds: 2),
    this.dotColor = Colors.white,
  }) : super(key: key);

  @override
  State<AnimatedDots> createState() => _AnimatedDotsState();
}

class _AnimatedDotsState extends State<AnimatedDots>
    with SingleTickerProviderStateMixin {
  late AnimationController _animationController;
  late Animation<double> _animation;
  int _currentIndex = 0;

  @override
  void initState() {
    super.initState();

    _animationController = AnimationController(
      vsync: this,
      duration: widget.duration,
    );

    _animation = Tween<double>(
      begin: 0,
      end: 1,
    ).animate(_animationController);

    _animationController.addStatusListener((status) {
      if (status == AnimationStatus.completed) {
        _currentIndex++;
        if (_currentIndex >= widget.path.length - 1) {
          _currentIndex = 0;
        }

        _animationController.reset();
        _animationController.forward();
      }
    });

    _animationController.forward();
  }

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

  @override
  Widget build(BuildContext context) {
    return AnimatedBuilder(
      animation: _animation,
      builder: (context, child) {
        final value = _animation.value;
        final current = widget.path[_currentIndex];
        final next = widget.path[(_currentIndex + 1) % widget.path.length];

        final dots = List.generate(widget.dotCount, (index) {
          final dotValue = (value + index / widget.dotCount) % 1;
          final x = current.dx + (next.dx - current.dx) * dotValue;
          final y = current.dy + (next.dy - current.dy) * dotValue;

          return Positioned(
            left: x - widget.dotSize / 2,
            top: y - widget.dotSize / 2,
            child: Container(
              width: widget.dotSize,
              height: widget.dotSize,
              decoration: BoxDecoration(
                color: widget.dotColor,
                shape: BoxShape.circle,
              ),
            ),
          );
        });

        return Stack(
          children: dots,
        );
      },
    );
  }
}

使用

复制代码

body: Center(
        child: Container(
          color: Colors.black,
          width: 150,
          height: 150,
          child: const ElectricAnimated(
            duration: 3,
            path: [
              Offset(30, 0),
              Offset(30, 67),
              Offset(90, 67),
              Offset(90, 137),
            ],
          ),
        ),
      ),

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