JS实现GridView式的数据加载（带滚动条）

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1.滚动条：Scrollbar.js

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 }; })();

2.页面代码

<!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>

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