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      小菜前两天学习了以下 Animation 的基本动画，接下来小菜学习以下稍微进阶版的 Animation 动画。

复合动画

      小菜前两天学习的主要是基本的单一动画，当然多个动画效果集一身也是毫无问题的，小菜接下来尝试一个图片显隐性和缩放同时循环使用的 Demo；

1. addStatusListener 用来监听当前动画状态，即开始或结束；
2. addListener 用来坚挺动画过程，可获取实时 value 值；

AnimationController controller;
Animation<double> animation, sizeAnim;@override
void initState() {super.initState();controller = AnimationController(duration: const Duration(milliseconds: 2000), vsync: this);animation = Tween(begin: 0.0, end: 1.0).animate(controller);sizeAnim = Tween(begin: 0.0, end: 180.0).animate(controller);animation.addStatusListener((status) {if (status == AnimationStatus.completed) {controller.reverse();} else if (status == AnimationStatus.dismissed) {controller.forward();}});sizeAnim.addStatusListener((status) {if (status == AnimationStatus.completed) {controller.reverse();} else if (status == AnimationStatus.dismissed) {controller.forward();}});
}Widget bodyWid() {return Center(child: Opacity(opacity: animation.value,child: FlutterLogo(size: sizeAnim.value)));
}

时间段动画

      既然可以监听动画过程和动画状态，整体的动画便可以灵活掌握；小菜接下来尝试一下分时间段动画，前 50% 显隐性处理，后 50% 缩放处理；

AnimationController controller;
Animation<double> animation, sizeAnim;
@override
void initState() {super.initState();controller = AnimationController(duration: const Duration(milliseconds: 2000), vsync: this);animation = Tween<double>(begin: 0.0,end: 1.0,).animate(CurvedAnimation(parent: controller, curve: Interval(0.0, 0.5, curve: Curves.ease)));sizeAnim = Tween<double>(begin: 100.0,end: 180.0,).animate(CurvedAnimation(parent: controller,curve: Interval(0.5, 1.0, curve: Curves.fastOutSlowIn)));
}Widget bodyWid() {return Center(child: Opacity(opacity: animation.value,child: FlutterLogo(size: sizeAnim.value)));
}

自定义动画

      动画是灵活的，我们可以根据自己的需求自定义动画效果，小菜尝试一个圆环绕一个圆转圈；

AnimationController controller;
Animation<double> animation;@override
void initState() {super.initState();controller = AnimationController(duration: const Duration(milliseconds: 2000), vsync: this);animation = Tween(begin: -1.0, end: 1.0).animate(controller);
}class AnimationCanvas extends CustomPainter {Animation<double> animation;AnimationCanvas(this.animation);Paint _paint = Paint()..color = Colors.blue..strokeWidth = 4.0..style = PaintingStyle.stroke;@overridevoid paint(Canvas canvas, Size size) {canvas.save();canvas.drawCircle(Offset(300, 300.0), 150.0, _paint);canvas.restore();canvas.save();canvas.translate(150 * sin(pi * animation.value), 150 * cos(pi * animation.value));canvas.drawCircle(Offset(300, 300.0), 10.0, _paint..color = Colors.red);canvas.restore();}@overridebool shouldRepaint(CustomPainter oldDelegate) {return true;}
}

Hero 动画

      Hero 动画是 Flutter 提供的飞入式动画，主要用在页面间切换时动画，且返回时动画按原路返回；使用时设置两个页面间 tag 一致即可，方便简洁；

Widget bodyWid04() {return Container(child: Padding(padding: EdgeInsets.all(10.0),child: GestureDetector(child: Row(children: <Widget>[Hero(tag: 'user_header', child: FlutterLogo(size: 50.0)),Padding(padding: EdgeInsets.only(left: 12.0),child: Text('Flutter Ptoto'))]),onTap: () {Navigator.pushNamed(context, 'animateRoute01');})));
}

      小菜学习了一下稍进阶的动画，如果有问题的烦请多多指导！