先看看效果
1、绿色：
2、彩色：
3、背景色：
4、绿色逐渐变浅：
源代码：
<!DOCTYPE html><html><head> <meta http-equiv="Content-Type" content="text/html;charset=utf-8"><title>Code -by ZhenYu.Sha</title><style type="text/css">html, body {width: 100%;height: 100%;}body {background: #000;overflow: hidden;margin: 0;padding: 0;}</style></head><body> <canvas id="cvs"></canvas><script type="text/javascript">var cvs = document.getElementById("cvs");var ctx = cvs.getContext("2d");var cw = cvs.width = document.body.clientWidth;var ch = cvs.height = document.body.clientHeight;//动画绘制对象var requestAnimationFrame = window.requestAnimationFrame || window.mozRequestAnimationFrame || window.webkitRequestAnimationFrame || window.msRequestAnimationFrame;var codeRainArr = []; //代码雨数组var cols = parseInt(cw / 14); //代码雨列数var step = 16; //步长，每一列内部数字之间的上下间隔ctx.font = "bold 26px microsoft yahei"; //声明字体，个人喜欢微软雅黑function createColorCv() {//画布基本颜色ctx.fillStyle = "#242424";ctx.fillRect(0, 0, cw, ch);}//创建代码雨function createCodeRain() {for (var n = 0; n < cols; n++) {var col = [];//基础位置，为了列与列之间产生错位var basePos = parseInt(Math.random() * 300);//随机速度 3~13之间var speed = parseInt(Math.random() * 10) + 3;//每组的x轴位置随机产生var colx = parseInt(Math.random() * cw)//绿色随机var rgbr = 0;var rgbg = parseInt(Math.random() * 255);var rgbb = 0;//ctx.fillStyle = "rgb("+r+','+g+','+b+")"for (var i = 0; i < parseInt(ch / step) / 2; i++) {var code = {x: colx,y: -(step * i) - basePos,speed: speed,// text : parseInt(Math.random()*10)%2 == 0 ? 0 : 1 //随机生成0或者1text: ["a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o", "p", "q", "s", "t", "u", "v", "w", "x", "y", "z"][parseInt(Math.random() * 11)], //随机生成字母数组中的一个color: "rgb(" + rgbr + ',' + rgbg + ',' + rgbb + ")"}col.push(code);}codeRainArr.push(col);}}//代码雨下起来function codeRaining() {//把画布擦干净ctx.clearRect(0, 0, cw, ch);//创建有颜色的画布//createColorCv();for (var n = 0; n < codeRainArr.length; n++) {//取出列col = codeRainArr[n];//遍历列，画出该列的代码for (var i = 0; i < col.length; i++) {var code = col[i];if (code.y > ch) {//如果超出下边界则重置到顶部code.y = 0;} else {//匀速降落code.y += code.speed;}//1 颜色也随机变化//ctx.fillStyle = "hsl("+(parseInt(Math.random()*359)+1)+",30%,"+(50-i*2)+"%)";//2 绿色逐渐变浅// ctx.fillStyle = "hsl(123,80%,"+(30-i*2)+"%)";//3 绿色随机// var r= 0;// var g= parseInt(Math.random()*255) + 3;// var b= 0;// ctx.fillStyle = "rgb("+r+','+g+','+b+")";//4 一致绿ctx.fillStyle = code.color;//把代码画出来ctx.fillText(code.text, code.x, code.y);}}requestAnimationFrame(codeRaining);}//创建代码雨createCodeRain();//开始下雨吧 GO>>requestAnimationFrame(codeRaining);</script></body></html>
更多代码雨的文章请参考我的其它文章：
“代码雨”js+css+html实现：/u014597198/article/details/71423269
