Flex里DropDownList默认值记录

Flex的s:DropDownList标签。 
我们很多web的应用中，例如，修改操作，某些字段是用下拉框显示的，那么当你查询出来的值返回到页面时候，要根据所传来的值，显示相应的下拉的值，这个操作在flex有点特别，代码如下:

?

               //下拉框的数据集

public static var fileNameTypeDropDownList:ArrayCollection = new ArrayCollection([

            {id:0,label:'Flag文件'},

            {id:1,label:'固定文件名'},

            {id:2,label:'正则表达式'}

]);

 

//获取DropDownList选中元素的索引

public static function getSelectedIndexByResult(list:ArrayCollection, key:String, result:Object):int{

            var selectedIndex:int = 0;

            try{

                for(var i:int = 0; i<list.length; i++){

                    if(list[i][key] == result){

                        selectedIndex = i;

                        break;

                    }

                }

            }catch(e:Error){Alert.show(e.message);}

            return selectedIndex;

}

 

var index:int = this.getSelectedIndexByResult(fileNameTypeDropDownList,'id',data['file_name'])

 

//mxml使用

<s:DropDownList id="userGroupComboBox" selectedIndex={index} requireSelection="true" dataProvider="{fileNameTypeDropDownList}" labelField="USER_GROUP_NAME"/>