使用自定义 itemRenderer 在 AdvancedDataGrid 之间进行 Flex 拖放答案

【问题标题】：Flex Drag and Drop between AdvancedDataGrid with custom itemRenderer使用自定义 itemRenderer 在 AdvancedDataGrid 之间进行 Flex 拖放
【发布时间】：2011-02-26 04:43:46
【问题描述】：

我已经实现了 2 个 AdvancedDataGrid 之间的拖放，但 Flex 的默认行为使用显示所有 5 列的网格项渲染器在拖动期间显示行数据。

相反，我想在拖动过程中显示图标/图像或我自己的自定义项目渲染器和下降。最简单的方法是什么？

有什么例子吗？

谢谢！

【问题讨论】：

标签： apache-flex drag-and-drop itemrenderer advanceddatagrid

【解决方案1】：

子类AdvancedDataGrid 并覆盖一个属性：

public class MyAdvancedDataGrid extends AdvancedDataGrid
{

    public function MyAdvancedDataGrid()
    {
        super();
    }

    [Embed("script.png")]
    private var scriptClass:Class;

    override protected function get dragImage():IUIComponent
    {
        var image:Image = new Image();
        image.source = scriptClass;
        image.owner = this;
        image.moduleFactory = moduleFactory;
        return image; 
    }
}

【讨论】：

【解决方案2】：

您可以使用拖动代理属性来指定图像。来自Adobe's online examples：

<?xml version="1.0"?>
<!-- dragdrop\DandDImageProxy.mxml -->
<mx:Application xmlns:mx="http://www.adobe.com/2006/mxml">

    <mx:Script>
        <![CDATA[
            //Import classes so you don't have to use full names.
            import mx.managers.DragManager;
            import mx.core.DragSource;
            import mx.events.DragEvent;
            import flash.events.MouseEvent;

            // Embed icon image.
            [Embed(source='assets/globe.jpg')]
            public var globeImage:Class;

            // The mouseMove event handler for the Image control
            // initiates the drag-and-drop operation.
            private function mouseOverHandler(event:MouseEvent):void 
            {                
                var dragInitiator:Image=Image(event.currentTarget);
                var ds:DragSource = new DragSource();
                ds.addData(dragInitiator, "img");               

                // The drag manager uses the Image control 
                // as the drag proxy and sets the alpha to 1.0 (opaque),
                // so it appears to be dragged across the Canvas.
                var imageProxy:Image = new Image();
                imageProxy.source = globeImage;
                imageProxy.height=15;
                imageProxy.width=15;                
                DragManager.doDrag(dragInitiator, ds, event, 
                    imageProxy, -15, -15, 1.00);
            }

            // The dragEnter event handler for the Canvas container
            // enables dropping.
            private function dragEnterHandler(event:DragEvent):void {
                if (event.dragSource.hasFormat("img"))
                {
                    DragManager.acceptDragDrop(Canvas(event.currentTarget));
                }
            }

            // The dragDrop event handler for the Canvas container
            // sets the Image control's position by 
            // "dropping" it in its new location.
            private function dragDropHandler(event:DragEvent):void {
                Image(event.dragInitiator).x = 
                    Canvas(event.currentTarget).mouseX;
                Image(event.dragInitiator).y = 
                    Canvas(event.currentTarget).mouseY;
            }
        ]]>
    </mx:Script>

    <!-- The Canvas is the drag target --> 
    <mx:Canvas id="v1" 
        width="500" height="500"  
        borderStyle="solid" 
        backgroundColor="#DDDDDD"
        dragEnter="dragEnterHandler(event);" 
        dragDrop="dragDropHandler(event);">

        <!-- The image is the drag initiator. -->
        <mx:Image id="myimg" 
            source="@Embed(source='assets/globe.jpg')" 
            mouseMove="mouseOverHandler(event);"/> 
    </mx:Canvas>
</mx:Application>

【讨论】：