jQuery自定义多选下拉框效果

项目中需要自定义一个下拉框多选插件，业务问题还是自己实现比较好

通过$.fn 向jQuery添加新的方法

下拉数据通过参数传递进去，通过调用该插件时接收，选择后的确定与取消事件采用事件传递方式

代码如下：

1.效果图

2.代码

<div id="demo" class="dropdown-container">
 <div class="dropdown-display">
  <span></span>
  <input type="text" class="iptdiplay" placeholder="请选择" readonly="readonly" />
 </div>
 <div class="dropdown-panel">
  <div class="dropdown-search">
  <span></span>
  <input type="text" class="iptsearch" placeholder="关键字搜索" />
  </div>
  <ul class="dd-select">
  <!-- area for dropdown items -->
  </ul>
  <div class="dropdown-opt">
  <button class="dd-btn ok">确定</button>
  <button class="dd-btn cancel">取消</button>
  </div>
 </div>
 </div>

.dropdown-container{
 display: block;
 width: 200px;
 height: 30px;
 padding: 0px;
 position: relative;
 margin: 0px auto;
}

.dropdown-display{
 display: block;
 height: 30px;
 position: absolute;
 top: 0;
 width:100%;
 margin: 0px;
 border:1px solid steelblue;
}
.dropdown-display span{
 background: url(../static/choose_down_icon_01.png) no-repeat left 8px;
 display: block;
 height: 25px;
 width: 10px;
 position: absolute;
 right: 5px;
 top: 3px;
}
.dropdown-display input[class='iptdiplay']{
 border: none;
 border-color: transparent;
 background: transparent;
 border-radius: 0px;
 box-shadow: none;
 height: 30px;
 width: 100%;
 margin: 0px;
 box-sizing: border-box;
 box-shadow: none;
 padding-left: 10px;
 padding-right: 18px;
 outline: none;
 cursor: pointer;
 text-overflow: ellipsis;
}
.dropdown-panel {
 position: absolute;
 top: 32px;
 width:100%;
 padding: 0px;
 display: none;
 border-left: 1px solid steelblue;
 border-bottom: 1px solid steelblue;
 border-right: 1px solid steelblue;
}

.dropdown-panel .dropdown-search{
 display: block;
 width: 100%;
 height: 30px;
}
.dropdown-search span{
 background: url(../static/chosen-sprite.png) no-repeat 100% -20px,linear-gradient(#eee 1%,#fff 15%);
 display: block;
 height: 25px;
 width: 20px;
 position: absolute;
 right: 0px;
 top: 3px;
}
.dropdown-search input[class='iptsearch']{
 border: none;
 border-color: transparent;
 background: transparent;
 border-radius: 0px;
 box-shadow: none;
 height: 30px;
 width: 100%;
 margin: 0px;
 box-sizing: border-box;
 box-shadow: none;
 padding-left: 10px;
 outline: none;
}
.dropdown-panel .dd-select{
 display: block;
 width:100%;
 position: relative;
 height: auto;
 margin: 0px;
 padding:0px !important;
 box-sizing: border-box;
 list-style-type: none;
 text-align: left;
 max-height: 300px;
 overflow-y: scroll;
 overflow-x: hidden;
}
.dd-item{
 display: block;
 height: 30px;
 line-height: 30px;
 padding-left: 5px;
 border-bottom: 1px solid steelblue;
 font-size: 13px;
 z-index: 8;
 overflow: hidden;
}
.dd-item .dd-v{
 width: 0px;
 height: 0px;
 display: none;
}
.dd-item .dd-k{
 z-index: 8;
 padding-left: 15px;
}
.dd-item:first-child{
 border-top: 1px solid steelblue;
}
.dd-item:last-child{
 border-bottom: none;
}
.dd-select .on{
 background-color: steelblue\9;
}
.dd-item:hover::before,.dd-item:hover before{
 content:'\2714';
 position: absolute;
 left: 0px;
 color: #79a979
 z-index: 9;
 font-size: 16px;
 padding-right: 3px;
 padding-left: 2px;
 background-color: #fff;
}
.dd-select .on::before,.dd-select .on before{
 content:'\2714';
 position: absolute;
 left: 0px;
 color: green;
 z-index: 9;
 font-size: 16px;
 padding-right: 3px;
 padding-left: 2px;
 background-color: #fff;
}
.dd-item:hover{
 cursor: pointer;
 background-color: #ccc;
}
.dropdown-container .dropdown-opt{
 width:100%;
 text-align: center;
 position: absolute;
 left: -1px;
 bottom: -30px;
 padding: 0px;
 border-left: 1px solid steelblue;
 border-bottom: 1px solid steelblue;
 border-right: 1px solid steelblue;
 box-sizing: content-box;
}
.dropdown-container .dd-btn{
 color: #333;
 height: 28px !important;
 display: inline-block;
 background-color: #e6e6e6;
 border-color: #adadad;
 user-select: none;
 background-image: none;
 border: 1px solid transparent;
 border-radius: 4px;
 margin: 0px 15px;
}
.dropdown-container .dd-btn:hover{
 color:#fff;
 background-color: steelblue;
}
/* scrollbar */
.dropdown-container ::-webkit-scrollbar { width: 5px; height: 10px; }
.dropdown-container ::-webkit-scrollbar-track,
.dropdown-container ::-webkit-scrollbar-thumb { border-radius: 999px; border: 5px solid transparent; }
.dropdown-container ::-webkit-scrollbar-track { box-shadow: 1px 1px 5px rgba(0,0,0,.2) inset; }
.dropdown-container ::-webkit-scrollbar-thumb { min-height: 20px; background-clip: content-box; box-shadow: 0 0 0 5px rgba(0,0,0,.2) inset; }
.dropdown-container ::-webkit-scrollbar-corner { background: transparent; }

3.Jquery插件

;(function ($,window,document,undefined) {
 var _pluginName="jqDropdown";

 var defaults = {
  items:[]
 };

 var parm=[];

 //es5 filter hack
 if (!Array.prototype.filter){
   Array.prototype.filter = function(fun){
   var len = this.length;
   if (typeof fun != "function") throw new TypeError();
    var res = new Array();
   var _arg = arguments[1];
   for (var i = 0; i < len; i++){
     if (i in this){
     var val = this[i];
     if (fun.call(_arg, val, i, this)) res.push(val);
     }
   }
    return res;
   };
 }
 if(!Array.prototype.indexOf) {
  Array.prototype.indexOf = function (elem, startFrom) {
   var startFrom = startFrom || 0;
   if (startFrom > this.length) return -1;

   for (var i = 0; i < this.length; i++) {
    if (this[i] == elem && startFrom <= i) {
     return i;
    } else if (this[i] == elem && startFrom > i) {
     return -1;
    }
   }
   return -1;
  }
 }
 var init = function (o,opts,okFn,cancelFn) {
  var _panel=$(o);
  var _ul=_panel.find(".dd-select:eq(0)");

  function createDropItems(items,p){
   p=p||[];
   _ul.empty();
   var _curretVal=$(".iptdiplay").val();
   for(var i=0,len=items.length;i<len;i++){
    var _d=items[i];
    var _li='<li class="{{DC}}"> <span class="dd-v">{{DV}}</span><span class="dd-k">{{DK}}</span></li>';
    _ul.append(_li.replace(/{{DV}}/g, _d.val).replace(/{{DK}}/g,_d.name).replace(/{{DC}}/g,p.indexOf(_d.val.toString())>-1?'dd-item on':'dd-item'));
   }

   _panel.find('.dd-item').click(function(e){
    var $this=$(this);
    var _k_= $this.find('.dd-k:eq(0)').text()
    var _v_= $this.find('.dd-v:eq(0)').text();
    if($this.hasClass('on')){
     parm=parm.filter(function(t){ return t!=_v_; });
     $this.removeClass('on');
    }else{
     parm.push(_v_);
     $this.addClass('on');
    }

    var disArr=[];
    for(var i=0,len=items.length;i<len;i++){
     var _d=items[i];
     if(parm.indexOf(_d.val.toString())>-1) disArr.push(_d.name);
    }
    $(".iptdiplay").val(disArr.join('|'));
   });
  };

  //init to build dropdown items
  createDropItems(opts.items||[]);

  function toggleDrop(){

   $(".dropdown-panel").slideToggle();
  };

  //search
  $(".iptsearch").bind("input propertychange",function(e){
   if(!e) return;
   var _sk=e.currentTarget.value;
   var _items=opts.items||[];
   createDropItems(_items.filter(function(d){

    return d.name.indexOf(_sk)>-1;
   }),parm);
  });

  //Toggle dropdown
  $(".dropdown-display").click(function(){

   toggleDrop();
  });

  //OK button event
  $(".dropdown-opt button.ok").click(function(){
   toggleDrop();
   okFn&&okFn.apply(this,[parm]);
  });

  //Cancel button event
  $(".dropdown-opt button.cancel").click(function(){

   toggleDrop();
   cancelFn&&cancelFn.call(this);
  });
 };

 $.fn[_pluginName] = function (options,okFn,cancelFn) {

  var options = $.extend(defaults, options);
  return this.each(function () {

   init(this,options,okFn,cancelFn);
  });
 }
})(jQuery,window,document);

4.页面调用示例

<script>

 var data=[
  { name:'http://58.100.3.12',val:1 },
  { name:'http://44.168.4.13',val:2 },
  { name:'http://192.168.2.1/sdfsf/234234/234/2/34/23',val:3 },
  { name:'http://220.199.5.14',val:4 },
  { name:'http://127.1.62.15',val:5 },
  { name:'http://127.1.62.15',val:6 },
  { name:'http://127.1.62.15',val:7 },
  { name:'http://127.1.62.15',val:8 },
  { name:'http://127.1.62.15',val:9 },
  { name:'http://127.1.62.15',val:10 },
  { name:'http://127.1.62.15',val:11 },
  { name:'http://127.1.62.15',val:12 },
  { name:'http://127.1.62.15',val:13 },
  { name:'http://127.1.62.15',val:14},
  { name:'http://127.1.62.15',val:15 },
  { name:'http://127.1.62.15',val:16 },
  { name:'http://127.1.62.15',val:17 },
  { name:'http://127.1.62.15',val:18 },
  { name:'http://127.1.62.15',val:19 },
  { name:'http://127.1.62.15',val:20 },
  { name:'http://127.1.62.15',val:21 },
  { name:'http://127.1.62.15',val:22 },
  { name:'http://127.1.62.15',val:23 },
  { name:'http://127.1.62.15',val:24 },
  { name:'http://127.1.62.15',val:25 },
  { name:'http://127.1.62.15',val:26 },
  { name:'http://127.1.62.15',val:27 },
  { name:'http://127.1.62.15',val:28 },
  { name:'http://127.1.62.15',val:29 }
 ];

 $("#demo").jqDropdown({ items:data },function(e){

  console.dir(e);
 },function(){

  console.log('canceled by user !');
 });

 </script>

5.输出

6.不足

　　页面样式在不支持css3浏览器中显示有问题 后期需要改进

下拉数据为一次性渲染 如有需要 可设置滚动加载

下拉框滚动条的美化未兼容所有浏览器

搜索时检索数据直接源自页面数据 所有需要添加延迟处理 获取服务端数据

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