邮箱下拉自动填充选择示例代码附图

1.需要一个js文件：jquery.mailAutoComplete-3.1.js

(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);

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>

<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>