转

HTML5 Canvas实现全屏黑客帝国文字掉落效果

2026-05-02 08:58:20 279
分类：canvas 
<!DOCTYPE html>
<html>
<head>
    <meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
    <meta http-equiv="X-UA-Compatible" content="IE=edge">
    <meta name="viewport" content="width=device-width, initial-scale=1">
    <meta name="apple-mobile-web-app-capable" content="yes">
    <meta name="apple-touch-fullscreen" content="yes">
    <meta name="apple-mobile-web-app-status-bar-style" content="black">
    <meta name="full-screen" content="yes">
    <meta name="x5-fullscreen" content="true">
    <meta name="browsermode" content="application">
    <meta name="x5-page-mode" content="app">
    <style type="text/css">
        * {
            margin: 0;
            overflow: hidden;
        }

        canvas {
            display: block;
            cursor: none;
        }
    </style>
    <title>你电脑被黑了(点击或按F11全屏)</title>
    <script type="text/javascript">
        window.onload = function () {
            var c = document.getElementById("c");
            var ctx = c.getContext("2d");

            //使画布全屏
            c.height = window.innerHeight;
            c.width = window.innerWidth;

            //要掉落的文字
            var txts = "0123456789";
            //转换为数组
            txts = txts.split("");

            var font_size = 16;
            var columns = c.width / font_size; //计算纵队数

            var drops = [];
            //初始值
            for (var x = 0; x < columns; x++)
                drops[x] = 1;

            //窗体大小发生改变
            window.onresize = function () {
                //使绘图区域全屏
                c.height = window.innerHeight;
                c.width = window.innerWidth;
                columns = c.width / font_size; //计算纵队数
                for (var x = 0; x < columns; x++)
                    drops[x] = 1;
            }

            //进入全屏
            function requestFullScreen() {
                var de = document.documentElement;
                if (de.requestFullscreen) {
                    de.requestFullscreen();
                } else if (de.mozRequestFullScreen) {
                    de.mozRequestFullScreen();
                } else if (de.webkitRequestFullScreen) {
                    de.webkitRequestFullScreen();
                }
            }

            //添加点击监听事件（点击全屏）
            document.body.addEventListener('click', function () {
                requestFullScreen(); //调用全屏
            }, false);

            //绘制下落的文字
            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, c.width, c.height);

                ctx.fillStyle = "#0F0"; //文本颜色（绿色）
                ctx.font = font_size + "px arial";
                //逐行输出文字
                for (var i = 0; i < drops.length; i++) {
                    //随机取要输出的文字
                    var text = txts[Math.floor(Math.random() * txts.length)];
                    //输出文字，注意坐标的计算
                    ctx.fillText(text, i * font_size, drops[i] * font_size);

                    //如果绘满一屏或随机数大于0.95（此数可自行调整，效果会不同）
                    if (drops[i] * font_size > c.height || Math.random() > 0.95)
                        drops[i] = 0;

                    //用于Y轴坐标增加
                    drops[i]++;
                }
            }

            setInterval(draw, 33);//定时执行
        }
    </script>
</head>
<body>
    <canvas id="c">很抱歉，您的浏览器不支持该功能！</canvas>
</body>
</html>