Html5 canvas 绘制彩票走势图

因须要要实现一个类似彩票走势图的功能，初次学Html5 ，非常多地方不明白，前段时间也发帖请教过这个问题。也是没给个明白说话，在网上搜了非常多，也没有实现的样例，今天细致研究了下。发现事实上也不是非常难，现将代码贴出来。共同学习！

先来一张效果图：

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实现的代码：

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">

<head runat="server">

    <meta http-equiv="Content-Type" content="text/html; charset=utf-8" />

    <title></title>

    <script src="js/jquery-1.10.2.js"></script>

    <style>

        table { border: 0; margin: 0; border-collapse: collapse; border-spacing: 0; font-size: 11px; font-family: Arial; margin: 0 auto; }

        table td, table th { padding: 0; border: 1px solid #d8d8d8; height: 23px; width: 23px; text-align: center; color: #666; }

        table th { font-weight: bold; color: #000; }

    </style>

    <script type="text/javascript">

        $(function () {

            CreateTable();

            var ids = "";

            for (var i = 1; i < 31; i++) {

                ids+= "T" + i + "_" + Math.floor(1 + Math.random() * (31 - 1)) + ",";

            }

            ids = ids.substring(0, ids.length - 1);

            CreateLine(ids, 20, "#ff6600", "canvasdiv", "#d5d5d5");

        });

        function CreateTable() {

            var tbody = "";

            var head = "<tr>";

            for (var i = 1; i < 31; i++) {

                head += "<th>H" + i + "</th>";

                tbody += "<tr>";

                for (var j = 1; j < 31; j++) {

                    tbody += "<td id='T" + i + "_" + j + "'>" + j + "</td>";

                }

                tbody += "</tr>";

            }

            head += "</tr>";

            $("#zstable thead").html(head);

            $("#zstable tbody").html(tbody);

        }

        function CreateLine(ids, w, c, div, bg) {

            var list = ids.split(",");

            for (var j = list.length - 1; j > 0; j--) {

                var tid = $("#" + list[j]);

                var fid = $("#" + list[j - 1]);

                var f_width = fid.outerWidth();

                var f_height = fid.outerHeight();

                var f_offset = fid.offset();

                var f_top = f_offset.top;

                var f_left = f_offset.left;

                var t_offset = tid.offset();

                var t_top = t_offset.top;

                var t_left = t_offset.left;

                var cvs_left = Math.min(f_left, t_left);

                var cvs_top = Math.min(f_top, t_top);

                tid.css("background", bg).css("color", "red");

                fid.css("background", bg).css("color", "red");

                var cvs = document.createElement("canvas");

                cvs.width = Math.abs(f_left - t_left) < w ? w : Math.abs(f_left - t_left);

                cvs.height = Math.abs(f_top - t_top);

                cvs.style.top = cvs_top + parseInt(f_height / 2) + "px";

                cvs.style.left = cvs_left + parseInt(f_width / 2) + "px";

                cvs.style.position = "absolute";

                var cxt = cvs.getContext("2d");

                cxt.save();

                cxt.strokeStyle = c;

                cxt.lineWidth = 1;

                cxt.lineJoin = "round";

                cxt.beginPath();

                cxt.moveTo(f_left - cvs_left, f_top - cvs_top);

                cxt.lineTo(t_left - cvs_left, t_top - cvs_top);

                cxt.closePath();

                cxt.stroke();

                cxt.restore();

                $("#" + div).append(cvs);

            }

        }

    </script>

</head>

<body>

    <form id="form1" runat="server">

        <table id="zstable">

            <thead></thead>

            <tbody></tbody>

        </table>

        <div id="canvasdiv">

        </div>

    </form>

</body>

</html>