效果图
html结构
<!DOCTYPE html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge">
<title>canvas33</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 = 1200;
canvas.height = 800;
var context = canvas.getContext("2d");
context.globalAlpha = 0.8;
for(var i = 0;i<100;i++){
var R = Math.floor(Math.random()*255);
var G = Math.floor(Math.random()*255);
var B = Math.floor(Math.random()*255);
context.fillStyle = "rgb("+R+","+G+","+B+")";
context.beginPath();
context.arc(Math.random()*canvas.width,Math.random()*canvas.height,Math.random()*100,0,Math.PI*2);
context.fill();
}
}
</script>
本文出自 “素颜” 博客，请务必保留此出处http://suyanzhu.blog.51cto.com/8050189/1892983
原文：http://suyanzhu.blog.51cto.com/8050189/1892983