Flex拖拽 Canvas容器里拖动Box

2009-02-18
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Flex拖拽-Canvas容器里拖动Box
文章分类:Web前端关键字: flex, flex拖拽, canvas, box
<?xml version="1.0" encoding="utf-8"?>
<mx:WindowedApplication xmlns:mx="http://www.adobe.com/2006/mxml" layout="absolute">
<mx:Script>
<![CDATA[
import mx.core.IUIComponent;
import mx.containers.Box;
import mx.containers.Canvas;
import mx.events.DragEvent;
import mx.managers.DragManager;
import mx.core.DragSource;
import mx.core.UIComponent;
private static const FORMAT:String = "box";
private function boxMouseDownHandler(evt:MouseEvent):void{
var iu:IUIComponent = evt.currentTarget as IUIComponent;
var dragSource:DragSource = new DragSource();
dragSource.addData( iu, FORMAT );
DragManager.doDrag( iu, dragSource, evt );
}

private function canvasDragEnterHandler(evt:DragEvent):void{
if(evt.dragSource.hasFormat(FORMAT)){
DragManager.acceptDragDrop(Canvas(evt.currentTarget));
}
}

private function canvasDragHandler(evt:DragEvent):void{
var box:Box = Box(evt.dragInitiator);
box.x = evt.localX;
box.y = evt.localY;
}
]]>
</mx:Script>

<mx:Canvas backgroundColor="0xEEEEEE" width="500" height="200" horizontalCenter="0" verticalCenter="0" dragEnter="canvasDragEnterHandler(event)" dragDrop="canvasDragHandler(event)">
<mx:Box width="20" height="20" backgroundColor="0x00FFCC" x="137" y="66" mouseDown="boxMouseDownHandler(event);"></mx:Box>
</mx:Canvas>
</mx:WindowedApplication>
当<mx:Box>发出mouseDown事件时，boxMouseDownHandler 方法被调用并且拖拽源数据被增加到DragManager。
canvasDragEnterHandler检查拖拽源的格式
释放时canvasDragHandler方法改变拖拽源的位置