做网站后台用什么语言,广安市网站建设公司,wordpress如何给头部加个搜索,怎么自己弄网站之前用 Flutter Canvas 画过一个三角三角形#xff0c;html 的 Canvas 也画过一次类似的#xff0c; 今天用 Flutter Canvas 试了下 感觉差不多#xff1a; html 版本 大致效果如下#xff1a; 思路和 html 实现的类似#xff1a; 也就是找出点的位置#xff0c;使用二阶… 之前用 Flutter Canvas 画过一个三角三角形html 的 Canvas 也画过一次类似的 今天用 Flutter Canvas 试了下 感觉差不多 html 版本 大致效果如下 思路和 html 实现的类似 也就是找出点的位置使用二阶贝塞尔曲线实现 代码如下
import package:flutter/material.dart;class PageCanvas extends StatefulWidget {const PageCanvas({Key? key}) : super(key: key);overrideStatePageCanvas createState() _PageCanvasState();
}class _PageCanvasState extends StatePageCanvas with TickerProviderStateMixin {late Animationdouble animation;late AnimationController controller;double _waveHeight 0.5;overridevoid initState() {// TODO: implement initStatesuper.initState();controller AnimationController(duration: const Duration(milliseconds: 2000), vsync: this);animation Tweendouble(begin: 0, end: 1).animate(controller);controller.repeat();}overrideWidget build(BuildContext context) {Size size MediaQuery.of(context).size;return Scaffold(appBar: AppBar(title: const Text(Canvas),backgroundColor: Colors.blue,),body: Column(children: [AnimatedBuilder(animation: controller,builder: (context, widget) {return CustomPaint(size: Size(size.width, size.height / 3),painter: MyPainter(animation.value, _waveHeight),);}),const SizedBox(height: 60,),Center(child: SizedBox(// color: Colors.grey,width: 200,height: 200,child: ClipOval(child: Container(color: Colors.grey.withOpacity(0.3),child: AnimatedBuilder(animation: controller,builder: (context, widget) {return CustomPaint(size: Size(size.width, size.height / 3),painter: MyPainter2(animation.value, _waveHeight),);}),),),),),const SizedBox(height: 20,),Slider(min: 0,max: 2,value: _waveHeight,onChanged: (value) {setState(() {_waveHeight value;});//_waveHeight value;},)],),);}overridevoid dispose() {controller.dispose();// TODO: implement disposesuper.dispose();}
}class MyPainter extends CustomPainter {final double value;final double waveHeight;const MyPainter(this.value, this.waveHeight);overridevoid paint(Canvas canvas, Size size) {// print(value);Paint paint Paint();Path path Path();double positionX -size.width * value;double positionY 100;double positionRange 5 * (1 waveHeight);double positionX2 -size.width * (1 - value);double positionY2 110;double positionRange2 10 * (1 waveHeight);double positionX3 -size.width * (1.3 - value);double positionY3 120;double positionRange3 20 * (1 waveHeight);double step size.width / 4;//path.moveTo(0 positionX, positionY);for (int i 1; i 13; i) {if (i % 2 1) {path.quadraticBezierTo(step * (2 * i - 1) positionX,positionY - positionRange, step * (2 * i) positionX, positionY);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX,positionY positionRange, step * (2 * i) positionX, positionY);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue.withOpacity(0.2);canvas.drawPath(path, paint);canvas.save();canvas.restore();path Path();path.moveTo(0 positionX2, positionY2);for (int i 1; i 13; i) {if (i % 2 1) {path.quadraticBezierTo(step * (2 * i - 1) positionX2,positionY2 - positionRange2,step * (2 * i) positionX2,positionY2);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX2,positionY2 positionRange2,step * (2 * i) positionX2,positionY2);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue.withOpacity(0.6);canvas.drawPath(path, paint);canvas.save();canvas.restore();path Path();path.moveTo(0 positionX3, positionY3);for (int i 1; i 13; i) {if (i % 2 1) {path.quadraticBezierTo(step * (2 * i - 1) positionX3,positionY3 - positionRange3,step * (2 * i) positionX3,positionY3);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX3,positionY3 positionRange3,step * (2 * i) positionX3,positionY3);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue;canvas.drawPath(path, paint);}overridebool shouldRepaint(covariant CustomPainter oldDelegate) {// TODO: implement shouldRepaintreturn oldDelegate ! this;//return true;}
}class MyPainter2 extends CustomPainter {final double value;final double waveHeight;const MyPainter2(this.value, this.waveHeight);overridevoid paint(Canvas canvas, Size size) {// print(value);Paint paint Paint();Path path Path();double positionX -size.width * value;double positionY 50;double positionRange 5 * (1 waveHeight);double positionX2 -size.width * (1 - value);double positionY2 60;double positionRange2 10 * (1 waveHeight);double positionX3 -size.width * (1.3 - value);double positionY3 70;double positionRange3 20 * (1 waveHeight);double step size.width / 4;//path.moveTo(0 positionX, positionY);for (int i 1; i 13; i) {if (i % 2 0) {path.quadraticBezierTo(step * (2 * i - 1) positionX,positionY - positionRange, step * (2 * i) positionX, positionY);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX,positionY positionRange, step * (2 * i) positionX, positionY);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue.withOpacity(0.2);canvas.drawPath(path, paint);canvas.save();canvas.restore();path Path();path.moveTo(0 positionX2, positionY2);for (int i 1; i 13; i) {if (i % 2 0) {path.quadraticBezierTo(step * (2 * i - 1) positionX2,positionY2 - positionRange2,step * (2 * i) positionX2,positionY2);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX2,positionY2 positionRange2,step * (2 * i) positionX2,positionY2);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue.withOpacity(0.6);canvas.drawPath(path, paint);canvas.save();canvas.restore();path Path();path.moveTo(0 positionX3, positionY3);for (int i 1; i 13; i) {if (i % 2 0) {path.quadraticBezierTo(step * (2 * i - 1) positionX3,positionY3 - positionRange3,step * (2 * i) positionX3,positionY3);} else {path.quadraticBezierTo(step * (2 * i - 1) positionX3,positionY3 positionRange3,step * (2 * i) positionX3,positionY3);}}path.lineTo(step * 10, 250);path.lineTo(0, 250);path.close();paint.color Colors.blue;canvas.drawPath(path, paint);canvas.save();canvas.restore();}overridebool shouldRepaint(covariant CustomPainter oldDelegate) {// TODO: implement shouldRepaintreturn oldDelegate ! this;//return true;}
}
