类似邮箱自动填充下拉效果

1.需要一个js文件：jquery.mailAutoComplete-3.1.js（原作者：zhangxinxu）

(function($){$.fn.mailAutoComplete = function(options){var defaults = {boxClass: "mailListBox", //外部box样式listClass: "mailListDefault", //默认的列表样式focusClass: "mailListFocus", //列表选样式中markCalss: "mailListHlignt", //高亮样式zIndex: 1,autoClass: true, //是否使用插件自带class样式mailArr: ["qq.com","gmail.com","126.com","163.com","hotmail.com","yahoo.com","yahoo.com.cn","live.com","sohu.com","sina.com"], //邮件数组textHint: false, //文字提示的自动显示与隐藏hintText: "",focusColor: "#333",blurColor: "#999"};var settings = $.extend({}, defaults, options || {});//页面装载CSS样式if(settings.autoClass && $("#mailListAppendCss").size() === 0){$('<style id="mailListAppendCss" type="text/css">.mailListBox{border:1px solid #369; background:#fff; font:12px/20px Arial;}.mailListDefault{padding:0 5px;cursor:pointer;white-space:nowrap;}.mailListFocus{padding:0 5px;cursor:pointer;white-space:nowrap;background:#369;color:white;}.mailListHlignt{color:red;}.mailListFocus .mailListHlignt{color:#fff;}</style>').appendTo($("head"));}var cb = settings.boxClass, cl = settings.listClass, cf = settings.focusClass, cm = settings.markCalss; //插件的class变量var z = settings.zIndex, newArr = mailArr = settings.mailArr, hint = settings.textHint, text = settings.hintText, fc = settings.focusColor, bc = settings.blurColor;//创建邮件内部列表内容$.createHtml = function(str, arr, cur){var mailHtml = "";if($.isArray(arr)){$.each(arr, function(i, n){if(i === cur){mailHtml += '<div class="mailHover '+cf+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';}else{mailHtml += '<div class="mailHover '+cl+'" id="mailList_'+i+'"><span class="'+cm+'">'+str+'</span>@'+arr[i]+'</div>';}});}return mailHtml;};//一些全局变量var index = -1, s;$(this).each(function(){var that = $(this), i = $(".justForJs").size();if(i > 0){ //只绑定一个文本框 return;}var w = that.outerWidth(), h = that.outerHeight(); //获取当前对象（即文本框）的宽高//样式的初始化that.wrap('<span style="display:inline-block;position:relative;"></span>').before('<div id="mailListBox_'+i+'" class="justForJs '+cb+'" style="min-width:'+w+'px;_width:'+w+'px;position:absolute;left:-6000px;top:'+h+'px;z-index:'+z+';"></div>');var x = $("#mailListBox_" + i), liveValue; //列表框对象that.focus(function(){//父标签的层级$(this).css("color", fc).parent().css("z-index", z);//提示文字的显示与隐藏if(hint && text){var focus_v = $.trim($(this).val());if(focus_v === text){$(this).val("");}}//键盘事件$(this).keyup(function(e){s = v = $.trim($(this).val());if(/@/.test(v)){s = v.replace(/@.*/, "");}if(v.length > 0){//如果按键是上下键if(e.keyCode === 38){//向上if(index <= 0){index = newArr.length;}index--;}else if(e.keyCode === 40){//向下if(index >= newArr.length - 1){index = -1;}index++;}else if(e.keyCode === 13){//回车if(index > -1 && index < newArr.length){//如果当前有激活列表$(this).val($("#mailList_"+index).text());}}else{if(/@/.test(v)){index = -1;//获得@后面的值//s = v.replace(/@.*/, "");//创建新匹配数组var site = v.replace(/.*@/, "");newArr = $.map(mailArr, function(n){var reg = new RegExp(site);if(reg.test(n)){return n;}});}else{newArr = mailArr;}}x.html($.createHtml(s, newArr, index)).css("left", 0);if(e.keyCode === 13){//回车if(index > -1 && index < newArr.length){//如果当前有激活列表x.css("left", "-6000px");}}}else{x.css("left", "-6000px");}}).blur(function(){if(hint && text){var blur_v = $.trim($(this).val());if(blur_v === ""){$(this).val(text);}}$(this).css("color", bc).unbind("keyup").parent().css("z-index",0);x.css("left", "-6000px");});//鼠标经过列表项事件//鼠标经过$(".mailHover").live("mouseover", function(){index = Number($(this).attr("id").split("_")[1]);liveValue = $("#mailList_"+index).text();x.children("." + cf).removeClass(cf).addClass(cl);$(this).addClass(cf).removeClass(cl);});});x.bind("mousedown", function(){that.val(liveValue);});});};})(jQuery);

2.jq库当然必不可少了，这里就略了

下面来测试

3.样式表：

<style type="text/css">        .out_box{border:1px solid #ccc; background:#fff; font:12px/20px Tahoma;}        .list_box{border-bottom:1px solid #eee; padding:0 5px; cursor:pointer;}        .focus_box{background:#f0f3f9;}        .mark_box{color:#c00;}    </style>

4.测试代码

<p>自定义class展示：<input type="text" id="customTest" size="28" /></p>        <script src="js/jquery-1.6.min.js" type="text/javascript"></script>    <script src="js/jquery.mailAutoComplete-3.1.js" type="text/javascript"></script>    <script type="text/javascript">        $(function() {            $("#customTest").mailAutoComplete({                boxClass: "out_box", //外部box样式                listClass: "list_box", //默认的列表样式                focusClass: "focus_box", //列表选样式中                markCalss: "mark_box", //高亮样式                autoClass: false,                textHint: true, //提示文字自动隐藏                hintText: "请输入邮箱地址"            });        })    </script>