jQuery自定义多选下拉框

　　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

 1 <div id="demo" class="dropdown-container">
 2     <div class="dropdown-display">
 3       <span></span>
 4       <input type="text" class="iptdiplay" placeholder="请选择" readonly="readonly" />
 5     </div>
 6     <div class="dropdown-panel">
 7       <div class="dropdown-search">
 8         <span></span>
 9         <input type="text"  class="iptsearch" placeholder="关键字搜索" />
10       </div>
11       <ul class="dd-select">
12         <!--  area for dropdown items -->
13       </ul>
14       <div class="dropdown-opt">
15         <button class="dd-btn ok">确定</button>
16         <button class="dd-btn cancel">取消</button>
17       </div>
18     </div>
19   </div>

  1 .dropdown-container{
  2     display: block;
  3     width: 200px;
  4     height: 30px;
  5     padding: 0px;
  6     position: relative;
  7     margin: 0px auto;
  8 }
  9 
 10 .dropdown-display{
 11     display: block;
 12     height: 30px;
 13     position: absolute;
 14     top: 0;
 15     width:100%;
 16     margin: 0px;
 17     border:1px solid steelblue;
 18 }
 19 .dropdown-display span{
 20     background: url(../static/choose_down_icon_01.png) no-repeat left 8px;
 21     display: block;
 22     height: 25px;
 23     width: 10px;
 24     position: absolute;
 25     right: 5px;
 26     top: 3px;
 27 }
 28 .dropdown-display input[class='iptdiplay']{
 29     border: none;
 30     border-color: transparent;
 31     background: transparent;
 32     border-radius: 0px;
 33     box-shadow: none;
 34     height: 30px;
 35     width: 100%;
 36     margin: 0px;
 37     box-sizing: border-box;
 38     box-shadow: none;
 39     padding-left: 10px;
 40     padding-right: 18px;
 41     outline: none;
 42     cursor: pointer;
 43     text-overflow: ellipsis;
 44 }
 45 .dropdown-panel {
 46     position: absolute;
 47     top: 32px;
 48     width:100%;
 49     padding: 0px;
 50     display: none;
 51     border-left: 1px solid steelblue;
 52     border-bottom: 1px solid steelblue;
 53     border-right: 1px solid steelblue;
 54 }
 55 
 56 .dropdown-panel .dropdown-search{
 57     display: block;
 58     width: 100%;
 59     height: 30px;
 60 }
 61 .dropdown-search span{
 62     background: url(../static/chosen-sprite.png) no-repeat 100% -20px,linear-gradient(#eee 1%,#fff 15%);
 63     display: block;
 64     height: 25px;
 65     width: 20px;
 66     position: absolute;
 67     right: 0px;
 68     top: 3px;
 69 }
 70 .dropdown-search input[class='iptsearch']{
 71     border: none;
 72     border-color: transparent;
 73     background: transparent;
 74     border-radius: 0px;
 75     box-shadow: none;
 76     height: 30px;
 77     width: 100%;
 78     margin: 0px;
 79     box-sizing: border-box;
 80     box-shadow: none;
 81     padding-left: 10px;
 82     outline: none;
 83 }
 84 .dropdown-panel .dd-select{
 85     display: block;
 86     width:100%;
 87     position: relative;
 88     height: auto;
 89     margin: 0px;
 90     padding:0px !important;
 91     box-sizing: border-box;
 92     list-style-type: none;
 93     text-align: left;
 94     max-height: 300px;
 95     overflow-y: scroll;
 96     overflow-x: hidden;
 97 }
 98 .dd-item{
 99     display: block;
100     height: 30px;
101     line-height: 30px;
102     padding-left: 5px;
103     border-bottom: 1px solid steelblue;
104     font-size: 13px;
105     z-index: 8;
106     overflow: hidden;
107 }
108 .dd-item .dd-v{
109     width: 0px;
110     height: 0px;
111     display: none;
112 }
113 .dd-item .dd-k{
114     z-index: 8;
115     padding-left: 15px;
116 }
117 .dd-item:first-child{
118     border-top: 1px solid steelblue;
119 }
120 .dd-item:last-child{
121     border-bottom: none;
122 }
123 .dd-select .on{
124     background-color: steelblue9;
125 }
126 .dd-item:hover::before,.dd-item:hover before{
127     content:'2714';
128     position: absolute;
129     left: 0px;
130     color: #79a979
131     z-index: 9;
132     font-size: 16px;
133     padding-right: 3px;
134     padding-left: 2px;
135     background-color: #fff;
136 }
137 .dd-select .on::before,.dd-select .on before{
138     content:'2714';
139     position: absolute;
140     left: 0px;
141     color: green;
142     z-index: 9;
143     font-size: 16px;
144     padding-right: 3px;
145     padding-left: 2px;
146     background-color: #fff;
147 }
148 .dd-item:hover{
149     cursor: pointer;
150     background-color: #ccc;
151 }
152 .dropdown-container .dropdown-opt{
153     width:100%;
154     text-align: center;
155     position: absolute;
156     left: -1px;
157     bottom: -30px;
158     padding: 0px;
159     border-left: 1px solid steelblue;
160     border-bottom: 1px solid steelblue;
161     border-right: 1px solid steelblue;
162     box-sizing: content-box;
163 }
164 .dropdown-container .dd-btn{
165     color: #333;
166     height: 28px !important;
167     display: inline-block;
168     background-color: #e6e6e6;
169     border-color: #adadad;
170     user-select: none;
171     background-image: none;
172     border: 1px solid transparent;
173     border-radius: 4px;
174     margin: 0px 15px;
175 }
176 .dropdown-container .dd-btn:hover{
177     color:#fff;
178     background-color: steelblue;
179 }
180 /* scrollbar */
181 .dropdown-container ::-webkit-scrollbar {  width: 5px;  height: 10px;  }  
182 .dropdown-container ::-webkit-scrollbar-track,  
183 .dropdown-container ::-webkit-scrollbar-thumb {  border-radius: 999px;  border: 5px solid transparent;  }  
184 .dropdown-container ::-webkit-scrollbar-track {  box-shadow: 1px 1px 5px rgba(0,0,0,.2) inset;  }  
185 .dropdown-container ::-webkit-scrollbar-thumb {  min-height: 20px;  background-clip: content-box;  box-shadow: 0 0 0 5px rgba(0,0,0,.2) inset;  }  
186 .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

【原创】

相关阅读:
磁共振中的T1， T2 和 T2*的原理和区别
 Revolver Maps-3D地球仪网站定制
 4种常见网络
 De Moivre–Laplace theorem
The Complex Inversion Formula. Bromwich contour.
理解全概率公式与贝叶斯公式（转）
滴滴数据
 ccs 分类
 dialog problem overview
recommendation baselines
原文地址：https://www.cnblogs.com/besuccess/p/6198017.html