juery 实现下拉框多选 jquery-multiselect

效果：



除了jquery，需要引用的样式和js文件：

<link rel="stylesheet" type="text/css" href="../assets/jquery.multiselect.css" />
<link rel="stylesheet" type="text/css" href="../assets/style.css" />
<link rel="stylesheet" type="text/css" href="../assets/prettify.css" />
<link href="../assets/jquery-ui.css" rel="stylesheet" />
<script src="../assets/jquery.js"></script>
<script src="../assets/jquery-ui.min.js"></script>
<script type="text/javascript" src="../assets/prettify.js"></script>
<script type="text/javascript" src="../assets/jquery.multiselect.js" charset=gb2312></script>

HTML代码：

<select title="Basic example" multiple="multiple" name="example-basic" size="5" id="ddlConditions">
<option value="1">Option 1</option>
<option value="2">Option 2</option>
<option value="3">Option 3</option>
<option value="4">Option 4</option>
<option value="5">Option 5</option>
<option value="6">Option 6</option>
<option value="7">Option 7</option>
</select>

默认选中值1，2，3，绑定指定的选项：

var  strcondition = '1,2,3';
var ids = strcondition.split(',');
if (ids != null) {
$('#ddlConditions').val(ids);
$('#ddlConditions').multiselect("refresh");
}

获取选中的多个值：

首先修改jquery.multiselect.js，添加全局变量multiValues ，用来存放选项值，然后修改update方法，添加multiValues 那一行代码：

update: function() {
var o = this.options;
var $inputs = this.inputs;
var $checked = $inputs.filter(':checked');
var numChecked = $checked.length;
var value;

if(numChecked === 0) {
value = o.noneSelectedText;
} else {
if($.isFunction(o.selectedText)) {
value = o.selectedText.call(this, numChecked, $inputs.length, $checked.get());
} else if(/\d/.test(o.selectedList) && o.selectedList > 0 && numChecked <= o.selectedList) {
value = $checked.map(function() { return $(this).next().html(); }).get().join(', ');
} else {
value = o.selectedText.replace('#', numChecked).replace('#', $inputs.length);
}
multiValues = $checked.map(function () { return $(this).val(); }).get().join(',');
}

this._setButtonValue(value);

return value;
},

再添加自定义方法：

MyValues:function(){
return multiValues;
},

页面使用此自定义方法，获取选中值的代码：

if ($('input[name=multiselect_ddlConditions]:checked').length < 1)
alert('Please Select Option');
else {
var strConditions = $("#ddlConditions").multiselect("MyValues");
}