首页 > 代码库 > canvas绘制五角形

canvas绘制五角形

效果图

技术分享

html结构

<!DOCTYPE html>

<html>

<head>

<meta charset="utf-8">

<meta http-equiv="X-UA-Compatible" content="IE=edge">

<title>canvas15</title>

<link rel="stylesheet" href="">

</head>

<body>

<canvas id="canvas" style ="border:1px solid #aaa;diplay:block;margin:50px auto;">

当前浏览器不支持canvas,请更换浏览器后再试

</canvas>

</body>

</html>

js脚本

<script>

window.onload = function(){

var canvas = document.getElementById("canvas");


canvas.width  = 800;

canvas.height = 800;


var context = canvas.getContext("2d");


drawStar(context,80,200,400,400,50,10,"#058");

}


function drawStar(context,r,R,x,y,rot,lineWidth,strokeStyle){

context.beginPath();


for(var i = 0;i<5;i++){

context.lineTo(Math.cos((18+i*72 - rot)/180 * Math.PI) * R + x,-Math.sin((18+i*72 - rot)/180*Math.PI)*R + y);

context.lineTo(Math.cos((54+i*72 - rot)/180 * Math.PI) * r + x,-Math.sin((54+i*72 - rot)/180*Math.PI)*r + y);

}


context.closePath();

context.lineWidth = lineWidth;

context.strokeStyle = strokeStyle;


context.stroke();

}

</script>


本文出自 “素颜” 博客,请务必保留此出处http://suyanzhu.blog.51cto.com/8050189/1892776

canvas绘制五角形