flutter 旋转指定角度的动画组件

import 'package:flutter/material.dart';

/// 旋转动画，旋转指定角度  动画 + Transform.rotate() 实现
class RotateContainer extends StatefulWidget{

  final double endAngle; // 旋转角度
  final bool rotated;    //是否旋转
  final Widget child;
  final int duration;    //旋转时间


  RotateContainer({this.endAngle,this.duration, this.rotated = false, this.child});

  @override
  State createState() {
    // TODO: implement createState
    return _RotateContainer();
  }
}

class _RotateContainer extends State with SingleTickerProviderStateMixin{

  AnimationController _controller;
  Animation _animation;
  double angle = 0;

  @override
  void initState() {
    // TODO: implement initState
    _controller = AnimationController(vsync: this,duration: Duration(milliseconds: widget.duration));
    _animation = Tween(begin: 0.0,end: widget.endAngle).animate(_controller)..addListener((){
      setState(() {
        angle = _animation.value;
      });
    });
    super.initState();
  }

  @override
  void didUpdateWidget(RotateContainer oldWidget) {
    // TODO: implement didUpdateWidget
    if(oldWidget.rotated == widget.rotated){
      return; //减少绘制
    }
    if(!widget.rotated){
      _controller.reverse();//反向旋转
    }else{
      _controller.forward();//正向旋转
    }
    super.didUpdateWidget(oldWidget);
  }

  @override
  void dispose() {
    // TODO: implement dispose
    _controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return Transform.rotate(angle: angle,child: widget.child,);
  }

}