写个一个简单的canvas图表

来源：互联网发布：python 读取mp4 编辑：程序博客网时间：2024/04/19 09:27

<!DOCTYPE html><html><head><meta charset="utf-8"><meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1"><title>canvas绘制图表</title><style type="text/css">*{margin:0;padding:0;}body{text-align:center;background-color:black;}#c1{background-color:white;}</style><script type="text/javascript">function rnd(n,m){return parseInt(Math.random()*(m-n)+n);}window.onload = function(){var canvas = document.getElementById('c1');var gd = canvas.getContext('2d');var aData = [100,200,300];var space = 20;var topSpace = 100;var iMax=Math.max.apply(null,aData)var w=40;var lastR=0;//前一个柱子的rightfor(var i=0;i<3;i++){var l=lastR+space;var h=(aData[i]/iMax)*(canvas.height-topSpace);var t=canvas.height-h;gd.fillStyle='rgb('+rnd(0, 256)+', '+rnd(0, 256)+', '+rnd(0, 256)+')';gd.fillRect(l,t,w,h);lastR=l+w;}}</script></head><body>    <canvas width='500' height="500" id="c1"></canvas></body></html>