SOURCE

(function($) {
    $.fn.ySelect = function(options) {
      var defaultOptions={
          placeholder: '请选择',
          numDisplayed: 4,
          overflowText: '{n} selected',
          searchText: '搜索',
          showSearch: true
      }
        if (typeof options == 'string' ) {
          var  settings = options;
        }
        else {

          var  settings = $.extend(true,{},defaultOptions, options);
        }


        /**
         * Constructor
         */
        function ySelect(select, settings) {
            this.$select = $(select);
            this.settings = settings;
            this.create();
        }


        /**
         * Prototype class
         */
        ySelect.prototype = {
            create: function() {
                var multiple = this.$select.is('[multiple]') ? ' multiple' : '';
                this.$select.wrap('<div class="fs-wrap' + multiple + '"></div>');
                this.$select.before('<div class="fs-label-wrap"><div class="fs-label">' + this.settings.placeholder + '</div><span class="fs-arrow"></span></div>');
                this.$select.before('<div class="fs-dropdown hidden"><div class="fs-options"></div></div>');
                this.$select.addClass('hidden');
                this.$wrap = this.$select.closest('.fs-wrap');
                this.reload();
            },

            reload: function() {
                if (this.settings.showSearch) {
                    var search = '<div class="fs-search"><input type="search" placeholder="' + this.settings.searchText + '" /><span class="fs-selectAll"><i class="fa fa-check-square-o"></i></span></div>';
                    this.$wrap.find('.fs-dropdown').prepend(search);
                }
                var choices = this.buildOptions(this.$select);
                this.$wrap.find('.fs-options').html(choices);
                this.reloadDropdownLabel();
            },

            destroy: function() {
                this.$wrap.find('.fs-label-wrap').remove();
                this.$wrap.find('.fs-dropdown').remove();
                this.$select.unwrap().removeClass('hidden');
            },

            buildOptions: function($element) {
                var $this = this;

                var choices = '';
                $element.children().each(function(i, el) {
                    var $el = $(el);

                    if ('optgroup' == $el.prop('nodeName').toLowerCase()) {
                        choices += '<div class="fs-optgroup">';
                        choices += '<div class="fs-optgroup-label">' + $el.prop('label') + '</div>';
                        choices += $this.buildOptions($el);
                        choices += '</div>';
                    }
                    else {
                        var selected = $el.is('[selected]') ? ' selected' : '';
                        choices += '<div class="fs-option' + selected + '" data-value="' + $el.prop('value') + '"><span class="fs-checkbox"><i></i></span><div class="fs-option-label">' + $el.html() + '</div></div>';
                    }
                });

                return choices;
            },

            reloadDropdownLabel: function() {
                var settings = this.settings;
                var labelText = [];

                this.$wrap.find('.fs-option.selected').each(function(i, el) {
                    labelText.push($(el).find('.fs-option-label').text());
                });

                if (labelText.length < 1) {
                    labelText = settings.placeholder;
                }
                else if (labelText.length > settings.numDisplayed) {
                    labelText = settings.overflowText.replace('{n}', labelText.length);
                }
                else {
                    labelText = labelText.join(', ');
                }

                this.$wrap.find('.fs-label').html(labelText);
                this.$select.change();
            },
            setwrap: function() {
              // if(settings.isCheck==false)
              //   this.$wrap.find('.fs-dropdown').addClass('hidden');
              return "123";
            },
        }


        /**
         * Loop through each matching element
         */
        return this.each(function() {
            var data = $(this).data('ySelect');

            if (!data) {
                data = new ySelect(this, settings);
                $(this).data('ySelect', data);
            }

            if (typeof settings == 'string') {
                data[settings]();
            }
        });
    }


    /**
     * Events
     */
    window.ySelect = {
        'active': null,
        'idx': -1
    };

    function setIndexes($wrap) {
        $wrap.find('.fs-option:not(.hidden)').each(function(i, el) {
            $(el).attr('data-index', i);
            $wrap.find('.fs-option').removeClass('hl');
        });
        $wrap.find('.fs-search input').focus();
        window.ySelect.idx = -1;
    }

    function setScroll($wrap) {
        var $container = $wrap.find('.fs-options');
        var $selected = $wrap.find('.fs-option.hl');

        var itemMin = $selected.offset().top + $container.scrollTop();
        var itemMax = itemMin + $selected.outerHeight();
        var containerMin = $container.offset().top + $container.scrollTop();
        var containerMax = containerMin + $container.outerHeight();

        if (itemMax > containerMax) { // scroll down
            var to = $container.scrollTop() + itemMax - containerMax;
            $container.scrollTop(to);
        }
        else if (itemMin < containerMin) { // scroll up
            var to = $container.scrollTop() - containerMin - itemMin;
            $container.scrollTop(to);
        }
    }

    $(document).on('click', '.fs-selectAll', function() {
        $(this).parent().next().find('.fs-option.selected').click();
        $(this).parent().next().find('.fs-option').click();
        $(this).addClass('selected');
    });
    $(document).on('click', '.fs-selectAll.selected', function() {
        $(this).parent().next().find('.fs-option.selected').click();
        $(this).removeClass('selected');
    });

    $(document).on('click', '.fs-option', function() {
        var $wrap = $(this).closest('.fs-wrap');

        if ($wrap.hasClass('multiple')) {
            var selected = [];

            $(this).toggleClass('selected');
            $wrap.find('.fs-option.selected').each(function(i, el) {
                selected.push($(el).attr('data-value'));
            });
        }
        else {
            var selected = $(this).attr('data-value');
            $wrap.find('.fs-option').removeClass('selected');
            $(this).addClass('selected');
            $wrap.find('.fs-dropdown').hide();
        }

        $wrap.find('select').val(selected);
        $wrap.find('select').ySelect('reloadDropdownLabel');
        $wrap.find('select').ySelect('setwrap');
    });
    $(document).on('keyup', '.fs-search input', function(e) {
        if (40 == e.which) {
            $(this).blur();
            return;
        }

        var $wrap = $(this).closest('.fs-wrap');
        var keywords = $(this).val();

        $wrap.find('.fs-option, .fs-optgroup-label').removeClass('hidden');

        if ('' != keywords) {
            $wrap.find('.fs-option').each(function() {
                var regex = new RegExp(keywords, 'gi');
                if (null === $(this).find('.fs-option-label').text().match(regex)) {
                    $(this).addClass('hidden');
                }
            });

            $wrap.find('.fs-optgroup-label').each(function() {
                var num_visible = $(this).closest('.fs-optgroup').find('.fs-option:not(.hidden)').length;
                if (num_visible < 1) {
                    $(this).addClass('hidden');
                }
            });
        }

        setIndexes($wrap);
    });

    $(document).on('click', function(e) {
        var $el = $(e.target);
        var $wrap = $el.closest('.fs-wrap');

        if (0 < $wrap.length) {
            if ($el.hasClass('fs-label')||$el.hasClass('fs-arrow')) {
                window.ySelect.active = $wrap;
                var is_hidden = $wrap.find('.fs-dropdown').hasClass('hidden');
                $('.fs-dropdown').addClass('hidden');

                if (is_hidden) {
                    $wrap.find('.fs-dropdown').removeClass('hidden');
                }
                else {
                    $wrap.find('.fs-dropdown').addClass('hidden');
                }

                setIndexes($wrap);
            }
        }
        else {
            $('.fs-dropdown').addClass('hidden');
            window.ySelect.active = null;
        }
    });

    $(document).on('keydown', function(e) {
        var $wrap = window.ySelect.active;

        if (null === $wrap) {
            return;
        }
        else if (38 == e.which) { // up
            e.preventDefault();

            $wrap.find('.fs-option').removeClass('hl');

            if (window.ySelect.idx > 0) {
                window.ySelect.idx--;
                $wrap.find('.fs-option[data-index=' + window.ySelect.idx + ']').addClass('hl');
                setScroll($wrap);
            }
            else {
                window.ySelect.idx = -1;
                $wrap.find('.fs-search input').focus();
            }
        }
        else if (40 == e.which) { // down
            e.preventDefault();

            var last_index = $wrap.find('.fs-option:last').attr('data-index');
            if (window.ySelect.idx < parseInt(last_index)) {
                window.ySelect.idx++;
                $wrap.find('.fs-option').removeClass('hl');
                $wrap.find('.fs-option[data-index=' + window.ySelect.idx + ']').addClass('hl');
                setScroll($wrap);
            }
        }
        else if (32 == e.which || 13 == e.which) { // space, enter
            $wrap.find('.fs-option.hl').click();
        }
        else if (27 == e.which) { // esc
            $('.fs-dropdown').addClass('hidden');
            window.ySelect.active = null;
        }
    });

    //update by ycx,for this plugin to get selected values
    $.fn.ySelectedValues=function (splitString)
      {
        var result="";
        var $selects=this.find("option:selected");
        for (var i = 0; i < $selects.length; i++) {
          result+=$selects[i].value+((i==$selects.length-1)?"":splitString);
        }
        return result;
      }
    $.fn.ySelectedTexts=function (splitString)
      {
        var result="";
        var $selects=this.find("option:selected");
        for (var i = 0; i < $selects.length; i++) {
          result+=$selects[i].text+((i==$selects.length-1)?"":splitString);
        }
        return result;
      }

})(jQuery);

<!doctype html>
<html>
<head>
<meta charset="utf-8">
<meta http-equiv="X-UA-Compatible" content="IE=edge,chrome=1">
<meta name="viewport" content="width=device-width, initial-scale=1">
<title>jQuery ySelect Plugin Demo</title>
<link rel="stylesheet" type="text/css" href="http://apps.bdimg.com/libs/bootstrap/3.3.4/css/bootstrap.css">
<link rel="stylesheet" type="text/css" href="http://cdn.bootcss.com/font-awesome/4.6.0/css/font-awesome.min.css">
<script src="http://cdn.bootcss.com/bootstrap/3.3.0/js/bootstrap.min.js"></script>
<script src="http://libs.baidu.com/jquery/2.1.4/jquery.min.js"></script>
</head>
<body>
<div class="container">
<select id='m1' class="demo" multiple="multiple">
    <optgroup label="产品">
        <option value="1">加多宝凉茶</option>
        <option value="2">饮料</option>
        <option value="3">太太乐鸡精</option>
        <option value="4">嘉士伯啤酒</option>
    </optgroup>
    <optgroup label="字典">
        <option value="5">成功图像类型</option>
        <option value="6">门店类型</option>
        <option value="7">终端类型</option>
    </optgroup>
</select>

<select class="demo" multiple="multiple">
    <optgroup label="产品">
        <option value="1">加多宝凉茶</option>
        <option value="2">饮料</option>
        <option value="3">太太乐鸡精</option>
        <option value="4">嘉士伯啤酒</option>
    </optgroup>
    <optgroup label="字典">
        <option value="5">成功图像类型</option>
        <option value="6">门店类型</option>
        <option value="7">终端类型</option>
    </optgroup>
</select>

<select id='m2' class="demo1" multiple="multiple" >
        <option value="1">加多宝凉茶</option>
        <option value="2">饮料</option>
        <option value="3">太太乐鸡精</option>
        <option value="4">嘉士伯啤酒</option>
        <option value="5">成功图像类型</option>
        <option value="6">门店类型</option>
</select>
<br/>
<button id="current" class="btn btn-primary btn-sm">查看值</button>
</div>


<script>
$(function() {
      $('.demo').ySelect();
     $('.demo1').ySelect( );
      $("#current").click(function(){
        alert($("#m1").ySelectedValues(","));
        alert($("#m1").ySelectedTexts(","));
      });

});
</script>
</body>
</html>

.fs-wrap {
    position: relative;
    display: inline-block;
    width: 200px;
    margin: 3px;
    font-size: 12px;
    line-height: 1;
}

.fs-label-wrap {
    position: relative;
    border: 1px solid #ccc;
    cursor: default;
    color: #555;
    border-radius: 4px;
    box-shadow: inset 0 1px 1px rgba(0,0,0,.075);
}

.fs-label-wrap,
.fs-dropdown {
    -webkit-user-select: none;
    -moz-user-select: none;
    -ms-user-select: none;
    user-select: none;
}

.fs-label-wrap .fs-label {
    padding: 4px 22px 4px 8px;
    text-overflow: ellipsis;
    white-space: nowrap;
    overflow: hidden;
    cursor: pointer;
}

.fs-arrow {
    width: 0;
    height: 0;
    border-left: 4px solid transparent;
    border-right: 4px solid transparent;
    border-top: 6px solid #000;
    position: absolute;
    top: 0;
    right: 4px;
    bottom: 0;
    margin: auto;
    cursor: pointer;
}

.fs-dropdown {
    position: absolute;
    background-color: #fff;
    border: 1px solid #ccc;
    /*margin-top: 2px;*/
    width: 100%;
    z-index: 1000;
    border-radius: 4px;
}

.fs-dropdown .fs-options {
    max-height: 200px;
    overflow: auto;
}

.fs-search input {
    width: 90%;
    padding: 2px 4px;
    border: 0;

}

.fs-selectAll {
    float: right;
    cursor: pointer;
    margin-top: 4px;
    height: auto;
}

.fs-selectAll.selected {
    float: right;
    cursor: pointer;
    margin-top: 4px;
    height: auto;
    color: green;
}

.fs-selectAll:hover{
    background-color: #eee;
}

.fs-option,
.fs-search,
.fs-optgroup-label {
    padding: 6px 8px;
    border-bottom: 1px solid #eee;
    cursor: default;
}

.fs-option {
    cursor: pointer;
}

.fs-option.hl {
    background-color: #f5f5f5;
}

.fs-wrap.multiple .fs-option {
    position: relative;
    padding-left: 30px;
}

.fs-wrap.multiple .fs-checkbox {
    position: absolute;
    display: block;
    width: 30px;
    top: 0;
    left: 0;
    bottom: 0;
}

.fs-wrap.multiple .fs-option .fs-checkbox i {
    position: absolute;
    margin: auto;
    left: 0;
    right: 0;
    top: 0;
    bottom: 0;
    width: 14px;
    height: 14px;
    border: 1px solid #aeaeae;
    border-radius: 4px;
    background-color: #fff;
}

.fs-wrap.multiple .fs-option.selected .fs-checkbox i {
    background-color: rgb(17, 169, 17);
    border-color: transparent;
    background-image: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAGCAYAAAD+Bd/7AAAABHNCSVQICAgIfAhkiAAAAAlwSFlzAAALEgAACxIB0t1+/AAAABx0RVh0U29mdHdhcmUAQWRvYmUgRmlyZXdvcmtzIENTNXG14zYAAABMSURBVAiZfc0xDkAAFIPhd2Kr1WRjcAExuIgzGUTIZ/AkImjSofnbNBAfHvzAHjOKNzhiQ42IDFXCDivaaxAJd0xYshT3QqBxqnxeHvhunpu23xnmAAAAAElFTkSuQmCC');
    background-repeat: no-repeat;
    background-position: center;
}


.fs-wrap .fs-option:hover {
    /*background-color: #f5f5f5;*/
    background: #D1F3E5;
    border-radius: 4px;
    margin-left:0px;
    margin-right:2px;
}

.fs-optgroup-label {
    font-weight: bold;
}

.hidden {
    display: none;
}

.fs-options::-webkit-scrollbar {
 width: 6px;
}
 .fs-options::-webkit-scrollbar-track {
 -webkit-border-radius: 2em;
 -moz-border-radius: 2em;
 border-radius:2em;
 -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
  background: rgba(0,0,0,0.1);
}
 .fs-options::-webkit-scrollbar-thumb {
   -webkit-box-shadow: inset 0 0 5px rgba(0,0,0,0.2);
  background: rgba(0,0,0,0.2);
 -webkit-border-radius: 2em;
 -moz-border-radius: 2em;
 border-radius:2em;
}