1.用法
在电脑桌面新建一个文本文档，然后将代码复制到文本文档里，再将后缀改为".html"。
2.效果图
3.html代码
<!DOCTYPE html>
<html>
<head><title>黑客帝国代码雨</title>
</head><body>
<canvas id="canvas"></canvas>
<style type="text/css">body{margin: 0; padding: 0; overflow: hidden;}
</style>
<script type="text/javascript">var canvas = document.getElementById('canvas');var ctx = canvas.getContext('2d');canvas.height = window.innerHeight;canvas.width = window.innerWidth;var texts = '0123456789#^%^&%^*^&*((*&%'.split('');var fontSize = 16;var columns = canvas.width/fontSize;// 用于计算输出文字时坐标，所以长度即为列数var drops = [];//初始值for(var x = 0; x < columns; x++){drops[x] = 1;}function draw(){//让背景逐渐由透明到不透明ctx.fillStyle = 'rgba(0, 0, 0, 0.05)';ctx.fillRect(0, 0, canvas.width, canvas.height);//文字颜色ctx.fillStyle = '#0F0';ctx.font = fontSize + 'px arial';//逐行输出文字for(var i = 0; i < drops.length; i++){var text = texts[Math.floor(Math.random()*texts.length)];ctx.fillText(text, i*fontSize, drops[i]*fontSize);if(drops[i]*fontSize > canvas.height || Math.random() > 0.95){drops[i] = 0;}drops[i]++;}}setInterval(draw, 33);
</script>
</body>
</html>
