<script src="~/Scripts/jquery-1.10.2.js"></script>

 <script src="~/Content/bootstrap/js/bootstrap.js"></script>
 <link href="~/Content/bootstrap/css/bootstrap.css" rel="stylesheet" />

 <script src="~/Content/select2-master/dist/js/select2.js"></script>
 <link href="~/Content/select2-master/dist/css/select2.css" rel="stylesheet" />


　　<select id="sel_menu2" multiple="multiple" class="form-control">
 <optgroup label="系統(tǒng)設(shè)置">
 <option value="1">用戶管理</option>
 <option value="2">角色管理</option>
 <option value="3">部門(mén)管理</option>
 <option value="4">菜單管理</option>
 </optgroup>
 <optgroup label="訂單管理">
 <option value="5">訂單查詢</option>
 <option value="6">訂單導(dǎo)入</option>
 <option value="7">訂單刪除</option>
 <option value="8">訂單撤銷</option>
 </optgroup>
 <optgroup label="基礎(chǔ)數(shù)據(jù)">
 <option value="9">基礎(chǔ)數(shù)據(jù)維護(hù)</option>
 </optgroup>
 </select>

 //多選
 $("#sel_menu2").select2({
 tags: true,
 maximumSelectionLength: 3 //最多能夠選擇的個(gè)數(shù)
 });

<select id="sel_menu" class="js-example-templating js-states form-control">
 <optgroup label="系統(tǒng)設(shè)置">
 <option value="1">用戶管理</option>
 <option value="2">角色管理</option>
 <option value="3">部門(mén)管理</option>
 <option value="4">菜單管理</option>
 </optgroup>
 <optgroup label="訂單管理">
 <option value="5">訂單查詢</option>
 <option value="6">訂單導(dǎo)入</option>
 <option value="7">訂單刪除</option>
 <option value="8">訂單撤銷</option>
 </optgroup>
 <optgroup label="基礎(chǔ)數(shù)據(jù)">
 <option value="9">基礎(chǔ)數(shù)據(jù)維護(hù)</option>
 </optgroup>
 </select>



$(function () {
 //帶圖片
 $("#sel_menu").select2({
 templateResult: formatState,
 templateSelection: formatState
 });
});

function formatState(state) {
 if (!state.id) { return state.text; }
 var $state = $(
 '<span><img src="/content/images/' + state.element.value.toLowerCase() + '.ico" class="img-flag" /> ' + state.text + '</span>'
 );
 return $state;
};

 <select id="sel_menu3" class="js-data-example-ajax form-control">
 <option value="3620194" selected="selected">請(qǐng)選擇</option>
 </select>

$(function () {
 //遠(yuǎn)程篩選
 $("#sel_menu3").select2({
 ajax: {
 url: "/Home/GetProvinces",
 dataType: 'json',
 delay: 250,
 data: function (params) {
 return {
 q: params.term, // search term
 page: params.page
 };
 },
 processResults: function (data, params) {
 params.page = params.page || 1;

 return {
 results: data.items,
 pagination: {
 more: (params.page * 10) < data.total_count
 }
 };
 },
 cache: true
 },
 escapeMarkup: function (markup) { return markup; }, // let our custom formatter work
 minimumInputLength: 1,
 templateResult: formatRepoProvince, // omitted for brevity, see the source of this page
 templateSelection: formatRepoProvince // omitted for brevity, see the source of this page
 });
});

function formatRepoProvince(repo) {
 if (repo.loading) return repo.text;
 var markup = "<div>"+repo.name+"</div>";
 return markup;
}

public List<string> lstProvince = new List<string>() {"北京市","天津市","重慶市","上海市","河北省","山西省","遼寧省","吉林省","黑龍江省","江蘇省","浙江省","安徽省","福建省","江西省","山東省","河南省","湖北省","湖南省","廣東省","海南省","四川省","貴州省","云南省","陜西省","甘肅省","青海省","臺(tái)灣省","內(nèi)蒙古自治區(qū)","廣西壯族自治區(qū)","西藏自治區(qū)","寧夏回族自治區(qū)","新疆維吾爾自治區(qū)","香港特別行政區(qū)","澳門(mén)特別行政區(qū)" };
 public JsonResult GetProvinces(string q, string page)
 {
 var lstRes = new List<Province>();
 for (var i = 0; i < 30; i++)
 {
 var oProvince = new Province();
 oProvince.id = i;
 oProvince.name = lstProvince[i];
 lstRes.Add(oProvince);
 }
 if (!string.IsNullOrEmpty(q.Trim()))
 {
 lstRes = lstRes.Where(x => x.name.Contains(q)).ToList();
 }
 var lstCurPageRes = string.IsNullOrEmpty(page) ? lstRes.Take(10) : lstRes.Skip(Convert.ToInt32(page) * 10 - 10).Take(10);
 return Json(new { items = lstCurPageRes, total_count = lstRes.Count }, JsonRequestBehavior.AllowGet);
 }

 var oMenuIcon = $("#txt_menuicon_web").select2({
 placeholder: "請(qǐng)選擇菜單圖標(biāo)",
 templateResult: oInit.formatState,
 templateSelection: oInit.formatState
 });
oMenuIcon.val();

 var oMenuIcon = $("#txt_menuicon_web").select2({
 placeholder: "請(qǐng)選擇菜單圖標(biāo)",
 templateResult: oInit.formatState,
 templateSelection: oInit.formatState
 });
 oMenuIcon.val("CA").trigger("change");