JS + HTml 時鐘代碼實現

時間 2019-11-21

標籤 html 時鐘代碼實現欄目 JavaScript 简体版

原文原文鏈接

JS+ Html 畫布實現的時鐘
效果圖：
javascript

閒來無聊作了一個網頁的時鐘，效果模擬傳統時鐘的運行方式，html

運用了html 的畫布實現指針，背景圖片引用了網絡圖片。java

具體原理：程序員

首先將時鐘分爲四個不一樣區域，對每一個區域計算cos，sin 來確實指針頂點位置。在經過畫布來繪畫出指針。
經過setInterval 每秒刷新指針位置實現傳統機械錶針的動態跳動。編程

本人是JS開發程序員，從業1年多。閒來無聊的簡單頁面，canvas

歡迎你們提問，或者建議。共同進步網絡

代碼部分，直接複製HTML 文件中便可查看效果：url

<!DOCTYPE html>
<html>
<head>
    <meta charset=utf-8>
    <title>clock</title>
</head>
<body style="color:green; <!--background-image:url('http://image.lxway.com/upload/b/f0/bf0d97dcee487096548e6edbc89d4963_thumb.png');--> background-size:100%; background-repeat: no-repeat; background-attachment:fixed">
    <div style="width: 900px; height: 900px; margin-top: 50px; margin-left: 50px;">
        <div style="position: absolute; left:119px;top: 193px; width: 900px; height: 900px; background-image:url('http://image.lxway.com/upload/b/f0/bf0d97dcee487096548e6edbc89d4963_thumb.png');  background-repeat: no-repeat; z-index: -1;">
        </div>
        <canvas id="t" width="800" height="800"></canvas>
        <div style="position: absolute; left:118px;top: 464px; width: 100px; height: 200px; background-color: white;  background-repeat: no-repeat; z-index: 10;">
        </div>
    </div>
    <script language="javascript">
                var s = setInterval(moveI, 1000);
                function moveI() {
                    var c = document.getElementById("t");
                    var pc = c.getContext("2d");
                    c.height = c.height;
                    //秒
                    pc.lineWidth = 3;
                    pc.strokeStyle = 'rgba(255,0,0,0.8)';
                    var now = new Date();
                    var sindex = getxy(150, now.getSeconds());
                    pc.moveTo(400, 400);
                    pc.lineTo(sindex.x, sindex.y);
                    pc.stroke();
                    pc.beginPath();
                    //分
                    pc.lineWidth = 7;
                    pc.strokeStyle = 'rgba(50,50,50,0.8)';
                    var mindex = getxy(120, now.getMinutes() + (now.getSeconds() / 60));
                    pc.moveTo(400, 400);
                    pc.lineTo(mindex.x, mindex.y);
                    pc.stroke();
                    pc.beginPath();
                    //時
                    pc.lineWidth = 10;
                    pc.strokeStyle = 'rgba(0,0,0,0.8)';
                    var hindex = getxy(80, ((now.getHours() > 12 ? now.getHours() - 12 : now.getHours()) + (now.getMinutes() / 60)) * 5);
                    pc.moveTo(400, 400);
                    pc.lineTo(hindex.x, hindex.y);
                    pc.stroke();
                };

                function getxy(r, t) {
                    //計算分區  0,1,2,3
                    var a = parseInt(t / 15);
                    //分區角度
                    t = t - 15 * a;
                    var y;
                    var x;
                    //基於分區的座標計算
                    switch (a) {
                        case 0:
                            y = r - (r * Math.cos(2 * Math.PI / 360 * 90 * (t / 15)));
                            x = r + (r * Math.sin(2 * Math.PI / 360 * 90 * (t / 15)));
                            break;
                        case 1:
                            y = r + (r * Math.sin(2 * Math.PI / 360 * 90 * (t / 15)));
                            x = r + (r * Math.cos(2 * Math.PI / 360 * 90 * (t / 15)));
                            break;
                        case 2:
                            y = r + (r * Math.cos(2 * Math.PI / 360 * 90 * (t / 15)));
                            x = r - (r * Math.sin(2 * Math.PI / 360 * 90 * (t / 15)));
                            break;
                        case 3:
                            y = r - (r * Math.sin(2 * Math.PI / 360 * 90 * (t / 15)));
                            x = r - (r * Math.cos(2 * Math.PI / 360 * 90 * (t / 15)));
                            break;
                        default:
                            break;
                    }
                    y = (400 - r) + y;
                    x = (400 - r) + x;
                    return {
                        'x': x,
                        'y': y
                    };
                };
    </script>
</body>

</html>