滚动分页几十万条数据也没有问题

function Scrollbar() {
    this.options = {
        total : 0, //数据总数
        pos : 0, //当前滚动位置
        itemSize : 20, //单项尺寸
        size : 200 //控件尺寸
    };
}
Scrollbar.prototype = (function () {
    function setOptions(options) {
        for (var attr in options) {
            this.options[attr] = options[attr];
        }
        Refresh(this);
    }
    function Refresh(_this) {
        if (!_this.created)
            return; //设置控件高度
        _this.bar.style.height = _this.options.size + "px";
        //设置内容高度
        var ch = _this.options.total * _this.options.itemSize;
        _this.content.style.height = ch + "px";
    }
    //获取滚动位置
    function getPos() {
        var top = this.bar.scrollTop;
        var pos = parseInt(top / this.options.itemSize);
        return pos;
    }
    //每页可展示的数据数量
    function getPageItems() {
        return this.options.size / this.options.itemSize;
    }
    //滚动事件响应
    function OnScroll(_this) {
        var pos = _this.getPos();
        if (pos == _this.options.pos)
            return;
        _this.options.pos = pos;
        _this.onScroll(pos);
    }
    //滚动条创建
    function CreateAt(dom) {
        var _this = this;
        var bar = document.createElement("div");
        var content = document.createElement("div");
        bar.appendChild(content);
        bar.style.width = "19px";
        bar.style.overflowY = "scroll";
        bar.style.overflowX = "hidden";
        if (bar.attachEvent) {
            bar.attachEvent("onscroll", function () {
                OnScroll(_this);
            });
        } else {
            //firefox兼容
            bar.addEventListener("scroll", function () {
                OnScroll(_this);
            }, false);
        }
        content.style.backgroundColor = "white";
        content.style.width = "1px";
        this.bar = bar;
        this.content = content;
        if (typeof(dom) == "string") {
            dom = document.getElementById(dom);
        }
        dom.innerHTML = "";
        dom.appendChild(this.bar);
        this.created = true;
        Refresh(this);
    }
    return {
        setOptions : setOptions,
        CreateAt : CreateAt,
        getPos : getPos,
        getPageItems : getPageItems,
        onScroll : null
        //模拟滚动条事件
    };
})();

 

 

 

 

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
<html xmlns="http://www.w3.org/1999/xhtml">
   
    <head>
        <title>
            表格控件
        </title>
        <script src="Scrollbar.js" type="text/javascript">
        </script>
        <script language="javascript" type="text/javascript">
            var data = [];
            //创建一万条示例数据
            for (var i = 0; i < 10000; i++) {
                var row = {
                    id: i,
                    text: "text" + i
                };
                data.push(row);
            }
            //创建滚动条
            var scrbar = new Scrollbar();
            window.onload = function() {
                scrbar.CreateAt("divScroll");
                scrbar.setOptions({
                    total: 10000,
                    size: 300
                });
                scrbar.onScroll = function(pos) {
                    ShowData(pos);
                }
                //获取模板
                var items = scrbar.getPageItems();
                var tpl = document.getElementById("trTpl");
                tpl.parentNode.removeChild(tpl);
                //仅创建所看到的几十行表格,所以自然快得多
                var list = document.getElementById("tblList");
                for (var i = 0; i < data.length && i < items; i++) {
                    var nr = tpl.cloneNode(true);
                    //从模板行复制新行
                    list.appendChild(nr);
                }
                ShowData(scrbar.getPos());
            }
            //根据滚动条,展示数据
            function ShowData(pos) {
                var n = scrbar.getPageItems();
                var rows = document.getElementById("tblList").rows;
                for (var i = 0; i < n; i++) {
                    var row = rows[i];
                    var item = data[i + pos];
                    row.cells["tdID"].innerHTML = item["id"];
                    row.cells["tdText"].innerHTML = item["text"];
                }
            }
        </script>
    </head>
   
    <body>
        <div id="divScroll" style="float:right">
        </div>
        <table border="1">
            <!--行标题-->
            <thead>
                <tr>
                    <th>
                        ID
                    </th>
                    <th>
                        Text
                    </th>
                </tr>
            </thead>
            <!--数据展示区-->
            <tbody id="tblList">
                <tr id="trTpl">
                    <td id="tdID">
                    </td>
                    <td id="tdText">
                    </td>
                </tr>
            </tbody>
        </table>
    </body>

</html>

posted @ 2012-09-25 13:29  易独  阅读(367)  评论(0编辑  收藏  举报
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