flex CheckBoxList

/**

 * @author         

 * @date         2010-6-2

 * @description    多选控件 

 */

package com.founder.szecp.components

{

    import flash.events.Event;

    

    import mx.collections.ArrayCollection;

    import mx.collections.ICollectionView;

    import mx.collections.IList;

    import mx.collections.ListCollectionView;

    import mx.collections.XMLListCollection;

    import mx.containers.Tile;

    import mx.controls.Alert;

    import mx.controls.CheckBox;

    import mx.core.IUIComponent;

    import mx.core.Repeater;

    

    public class CheckBoxList extends Tile

    {                

        protected var collection:ICollectionView;            //显示的数据源

        private var _labelField:String = "label";            //显示的数据字段

        private var _dataField : String = "";                //选中的状态

        private var _selectedName : String = "";            //设置选中的值

        private var _splitString : String = "，";            //设置选中值的分割符

        private var cellWidth:Number;

        private var cellHeight:Number;

        

        //数据源

        [Bindable("collectionChanged")]

        public function get dataProvider():Object

        {

            return collection;

        }

        

           

        [Bindable("collectionChanged")]

        public function set dataProvider(value:Object):void

        {

            if (value is Array)

            {

                collection = new ArrayCollection(value as Array);

            }

            else if (value is ICollectionView)

            {

                collection 




lor: #000000;">= ICollectionView(value);

            }

            else if (value is IList)

            {

                collection = new ListCollectionView(IList(value));

            }

            else if (value is XMLList)

            {

                collection = new XMLListCollection(value as XMLList);

            }

            else

            {

                // convert it to an array containing this one item

                var tmp:Array = [value];

                collection = new ArrayCollection(tmp);

            }            

            

            dispatchEvent(new Event("collectionChanged"));

            addChildren();

        }

        //显示字段

        [Bindable("labelFieldChanged")]

        public function get labelField():String

        {

            return _labelField;

        }

        

        public function set labelField(value:String):void

        {

            _labelField = value;

            dispatchEvent(new Event("labelFieldChanged"));

        }

        

        //设定选中的状态

        [Bindable("dataFieldChanged")]

        public function get dataField() : String

        {

            return _dataField;

        }

        public function set dataField(value : String) : void

        {

            _dataField = value;

            dispatchEvent(new Event("dataFieldChanged"));

        }

        //设定选中的值

        [Bindable("selectedValueChanged")]

        public function get selectedName() : String

        {

            var value : String = "";

            for each (var obj : Object in collection)

            {

                if(obj[dataField] == "true")

                    value += obj[labelField] + _splitString;

            }

            return value;

        }

        

        public function set selectedName(value : String) : void

        {

            _selectedName= value;

            for each(var o : Object in collection)

            {

                o[dataField] = "false";

            }          

            if(value != null) setSelectedName();

            addChildren();            

            dispatchEvent(new Event("selectedValueChanged"));

        }

        //设定分割符

        [Bindable("splitStringChanged")]

        public function get splitString() : String

        {

            return _splitString;    

        }

        

        public function set splitString(value : String) : void

        {

            _splitString = value;

            dispatchEvent(new Event("splitStringChanged"));

        }

        

        public function CheckBoxList()

        {

            super();

        }        

        

        //新增子列表

        private function addChildren() : void

        {

            this.removeAllChildren();

            if(collection == null) return;

            

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

            {

                   var cb : CheckBox = new CheckBox();

                   cb.selected= collection[i][dataField]=="true" ? true : false;

                cb.label = collection[i][labelField];                

                addChild(cb);                

            }

        }

        //拿到当前选中的对象列表

        public function getSelectedArrary() : Array

        {

            var arr : Array = new Array();

            for each (var obj : Object in collection)

            {

                if(obj[dataField] == "true")

                    arr.push(obj);

            }

            return arr;

        }

        

        protected override function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void

        {

            super.updateDisplayList(unscaledWidth,unscaledHeight);

            findCellSize();

            

            if(numChildren<=0) return ;            

            var horizontalGap:Number = getStyle("horizontalGap");

            var verticalGap:Number = getStyle("verticalGap");            

            var num : Number = Math.floor(width / (cellWidth + horizontalGap) );

            height = Math.ceil((cellHeight + verticalGap) * Math.ceil(numChildren/num));            

        }



        private function findCellSize():void

        {

            // If user explicitly supplied both a tileWidth and

            // a tileHeight, then use those values.

            var widthSpecified:Boolean = !isNaN(tileWidth);

            var heightSpecified:Boolean = !isNaN(tileHeight);

            if (widthSpecified && heightSpecified)

            {

                cellWidth = tileWidth;

                cellHeight = tileHeight;

                return;

            }

    

            // Reset the max child width and height

            var maxChildWidth:Number = 0;

            var maxChildHeight:Number = 0;

            

            // Loop over the children to find the max child width and height.

            var n:int = numChildren;

            for (var i:int = 0; i < n; i++)

            {

                var child:IUIComponent = IUIComponent(getChildAt(i));

    

                if (!child.includeInLayout)

                    continue;

                

                var Number = child.getExplicitOrMeasuredWidth();

                if (width > maxChildWidth)

                    maxChildWidth = width;

                

                var height:Number = child.getExplicitOrMeasuredHeight();

                if (height > maxChildHeight) 

                    maxChildHeight = height;

            }

            

            // If user explicitly specified either width or height, use the

            // user-supplied value instead of the one we computed.

            cellWidth = widthSpecified ? tileWidth : maxChildWidth;

            cellHeight = heightSpecified ? tileHeight : maxChildHeight;

        }

        

        private function setSelectedName() : void

        {                    

            var arr : Array = _selectedName.split(_splitString);

            

            for each (var obj : Object in collection)

            {

                for each(var str : String in arr)

                {

                    if(obj[labelField]==str) 

                        obj[dataField] = "true";

                }

            }            

        }

    }



} 

 用于flex3下多选

效果图

 

<ns1:CheckBoxList id="cblLocationName"

  dataProvider="{instanceBiz.eventReportEvtLocationArr}"

  dataField="descrp"

  labelField="typeValue"  

                  width="100%"/>