写一个带有“请选择的”的下拉框，需要用到 map（用于设置默认值）和 Array(用于填充数据)

var expressNameList = new Array();

var  expressNameMap= new Map();

$.ajax({
type: "post",
url: "${ctx}/staticData/query?typeCode=EXPRESS_NAME&dataCode=",
contentType: "application/json;charset=utf-8",
success: function(data) {
if (data != null && data.length > 0) {
$(eval(data)).each(function(){
expressNameMap.put(this.value,this.name);
expressNameList[expressNameList.length] = {itemText: this.name, itemData: this.value};
});
// 设置快递名称类型下拉列表
expressName = $("#qexpressName-dropdownlist").dropDownList({
inputName: "qexpressName",
inputValName: "qexpressNameId",
buttonText: "",
width: "117px",
readOnly: false,
required: true,
maxHeight: 200,
onSelect: function(i, data, icon) {},
items: expressNameList
});
expressName.setData("请选择", "0", "");
}
},
error: function(req, error, errObj) {
}
});

11 map的用法在grid栏显示数据的时候：{title:'快递名称',name:'expressName',width:100,sortable:true,align:'left' ,renderer: function (val, item, rowIndex){if (item && item.expressName) {return expressMap.get(item.expressName)}}},2.修改界面显示数据的时候：

                       $('#expressState').val(expressStateListMap.get(rowExpress.expressState).itemData);$('#expressStateId1').val(expressStateListMap.get(rowExpress.expressState).itemText);