[zt]Flex 3: 构建高级用户界面 添加拖放支持5

// from Wikipedia (http://en.wikipedia.org/wiki/Euro_coins)
[Embed("assets/1c.png")]
[Bindable]
public var OneCent:Class;
[Embed("assets/2c.png")]

[Bindable]
public var TwoCents:Class;
[Embed("assets/5c.png")]

[Bindable]
public var FiveCents:Class;
[Embed("assets/10c.png")]

[Bindable]
public var TenCents:Class;
[Bindable]

private var totalValue:uint;

private function dragIt(event:MouseEvent, value:uint):void
{

// Get the drag initiator component from the event object.
var dragInitiator:Image = event.currentTarget as Image;
// Create a DragSource object.
var dragSource:DragSource = new DragSource();
// Add the data to the object.

dragSource.addData(value, 'value');
// Create a copy of the coin image to use as a drag proxy.
var dragProxy:Image = new Image();
dragProxy.source = event.currentTarget.source;
// Call the DragManager doDrag() method to start the drag.

DragManager.doDrag(dragInitiator, dragSource, event, dragProxy);
}

// Called if the user drags a drag proxy onto the drop target.
private function dragEnterHandler(event:DragEvent):void
{

// Get the drop target component from the event object.
var dropTarget:Box=event.currentTarget as Box;
// Accept the drag only if the user is dragging data
// identified by the 'value' format value.

if (event.dragSource.hasFormat('value'))
{
// Make the border of the Box thicker to
// visually signal to the user that they can
// drop the coin there.

dropTarget.setStyle("borderThickness", 5);
// Accept the drop.
DragManager.acceptDragDrop(dropTarget);
}
}

// Called if the user drags the drag proxy away from the drop target.
private function dragExitHandler(event:DragEvent):void
{

// Get the drop target component from the event object.
var dropTarget:Box=event.currentTarget as Box;
// Set the border of the Box to its default value
// to visually indicate that the user is no longer
// over the drop target.

revertBoxBorder();
}
// Called if the target accepts the dragged object and the user
// releases the mouse button while over the drop target.
private function dragDropHandler(event:DragEvent):void
{

// Get the data identified by the color format from the drag source.
var value:uint = event.dragSource.dataForFormat('value') as uint;

// Add the value to the total

totalValue += value;
// Set the border of the Box to its default value
revertBoxBorder();
}
// Helper method to revert the Box's border to a 1 pixel outline.
private function revertBoxBorder():void

{
amountDisplay.setStyle("borderThickness", 1);
}
]]>

<hbox><br><image></image> id="oneCent" source="{OneCent}" <br> mouseMove="dragIt(event, 1);"</hbox>

/>
id="twoCents" source="{TwoCents}"
mouseMove="dragIt(event, 2);"

/>
id="fiveCents" source="{FiveCents}"
mouseMove="dragIt(event, 5);"

/>
id="tenCents" source="{TenCents}"
mouseMove="dragIt(event, 10);"

/>

<box></box> id="amountDisplay"
borderStyle="solid" borderColor="#000000" backgroundColor="#FFFFFF"

width="100%" height="100" horizontalAlign="center" verticalAlign="middle"

dragEnter="dragEnterHandler(event);"

dragExit="dragExitHandler(event);"
dragDrop="dragDropHandler(event);"

>