效果：
HTML代码：
<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="InputText.aspx.cs" Inherits="DropDownLikeBaiDu.InputText" %> <!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 runat="server">
<title></title>
<script src="input.js" type="text/javascript"></script>
</head>
<body style=" background-color:green">
<form id="form1" runat="server">
<div style="margin-left: 300px; margin-top: 300px;">
青苹果搜索：
<input type="text" id="SearchID" onfocus="javascript:if(this.value=='请输入内容')this.value='';"
onkeyup="autoComplete.start(event)" onblur="javascript:if(this.value=='')this.value='请输入内容';" />
<div class="auto_hidden" style="margin-left:100px; background-color:white" id="SearchLike">
<!--自动完成 DIV-->
</div>
</div>
</form>
</body>
<script>
var get_ID = document.getElementById("SearchID");
var get_Like = document.getElementById("SearchLike");
var autoComplete = new AutoComplete(get_ID, get_Like, ['中国', '*', '青苹果', '青菜', '青茶', '博客园', '博士', '博大精深']);
</script>
</html>
JS代码：
var Bind = function (object, fun) {
return function () {
return fun.apply(object, arguments);
}
}
function AutoComplete(obj, autoObj, arr) {
this.obj = obj; //输入框
this.autoObj = autoObj; //DIV的根节点
this.value_arr = arr; //不要包含重复值
this.index = -1; //当前选中的DIV的索引
this.search_value = ""; //保存当前搜索的字符
}
AutoComplete.prototype = {
//初始化DIV的位置
init: function () {
this.autoObj.style.left = this.obj.offsetLeft + "px";
this.autoObj.style.top = this.obj.offsetTop + this.obj.offsetHeight + "px";
this.autoObj.style.width = this.obj.offsetWidth - 2 + "px"; //减去边框的长度2px
},
//删除自动完成需要的所有DIV
deleteDIV: function () {
while (this.autoObj.hasChildNodes()) {
this.autoObj.removeChild(this.autoObj.firstChild);
}
this.autoObj.className = "auto_hidden";
},
//设置值
setValue: function (_this) {
return function () {
_this.obj.value = this.seq;
_this.autoObj.className = "auto_hidden";
}
},
//模拟鼠标移动至DIV时，DIV高亮
autoOnmouseover: function (_this, _div_index) {
return function () {
_this.index = _div_index;
var length = _this.autoObj.children.length;
for (var j = 0; j < length; j++) {
if (j != _this.index) {
_this.autoObj.childNodes[j].className = 'auto_onmouseout';
} else {
_this.autoObj.childNodes[j].className = 'auto_onmouseover';
}
}
}
},
//更改classname
changeClassname: function (length) {
for (var i = 0; i < length; i++) {
if (i != this.index) {
this.autoObj.childNodes[i].className = 'auto_onmouseout';
} else {
this.autoObj.childNodes[i].className = 'auto_onmouseover';
this.obj.value = this.autoObj.childNodes[i].seq;
}
}
},
//响应键盘
pressKey: function (event) {
var length = this.autoObj.children.length;
//光标键"↓"
if (event.keyCode == 40) {
++this.index;
if (this.index > length) {
this.index = 0;
} else if (this.index == length) {
this.obj.value = this.search_value;
}
this.changeClassname(length);
}
//光标键"↑"
else if (event.keyCode == 38) {
this.index--;
if (this.index < -1) {
this.index = length - 1;
} else if (this.index == -1) {
this.obj.value = this.search_value;
}
this.changeClassname(length);
}
//回车键
else if (event.keyCode == 13) {
this.autoObj.className = "auto_hidden";
this.index = -1;
} else {
this.index = -1;
}
},
//程序入口
start: function (event) {
if (event.keyCode != 13 && event.keyCode != 38 && event.keyCode != 40) {
this.init();
this.deleteDIV();
this.search_value = this.obj.value;
var valueArr = this.value_arr;
valueArr.sort();
if (this.obj.value.replace(/(^\s*)|(\s*$)/g, '') == "") { return; } //值为空，退出
try { var reg = new RegExp("(" + this.obj.value + ")", "i"); }
catch (e) { return; }
var div_index = 0; //记录创建的DIV的索引
for (var i = 0; i < valueArr.length; i++) {
if (reg.test(valueArr[i])) {
var div = document.createElement("div");
div.className = "auto_onmouseout";
div.seq = valueArr[i];
div.onclick = this.setValue(this);
div.onmouseover = this.autoOnmouseover(this, div_index);
//搜索到的字符粗体显示
div.innerHTML = valueArr[i].replace(reg, "<strong style=\"background-color:red\">$1</strong>");
this.autoObj.appendChild(div);
this.autoObj.className = "auto_show";
div_index++;
}
}
}
this.pressKey(event);
window.onresize = Bind(this, function () { this.init(); });
}
}
Demo下载：
http://files.cnblogs.com/files/xinchun/DropDownLikeBaiDu.zip