Flex拖拽技术(二)

<?xml version="1.0" encoding="utf-8"?>
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml" layout="vertical"

verticalAlign="middle" fontSize="12">
<mx:Script>
    <![CDATA[
    import mx.core.IUIComponent;
    import mx.events.DragEvent;
    import mx.core.DragSource;
    import mx.managers.DragManager;
        //拖动初始器
        private function dragSource(e:MouseEvent,format:String):void
        {
           var iu:IUIComponent = e.currentTarget as IUIComponent;
            var ds : DragSource = new DragSource();
            ds.addData( {"x" : e.localX, "y" : e.localY},format);//设置一个标号format
            DragManager.doDrag(iu,ds,e);
        }
        //当拖进去时
        private function onEnter( e:DragEvent,format:String ) : void
        {
            if(e.dragSource.hasFormat(format))//如果标号为format则接受拖来的物体
            {
                DragManager.acceptDragDrop(IUIComponent(e.target) );         
            }
        }
        //当拖完成时
        private function onDrop(e:DragEvent,format:String) : void
        {
            var myData:Object = new Object();
            myData = e.dragSource.dataForFormat(format);
            btn.x = this.mouseX - myData.x;//btn为按钮的id,要是扩展到其他组件，改这里就可以了。
            btn.y = this.mouseY - myData.y;
        }
    ]]>
</mx:Script>
<mx:Canvas y="40" id="cansAccess" backgroundColor="#000000" width="600" height="800"
dragEnter="onEnter(event,'formatString')" dragDrop="onDrop(event,'formatString')"/>
<mx:Button id="btn" label="拖动我到面板"   mouseDown="dragSource(event,'formatString')" />
</mx:Application>