你必须添加一个DisplayObject
当您致电时为您叠加并投保updateDisplayList
它位于另一个的顶部。
public var overlayEnabled:Boolean;
public overlayHolder:(whatever display object you want to use)
override protected updateDisplayList(...) {
super.updateDisplayList(...)
if (overlayEnabled) {
if (overlayHolder.parent != this){
addChild(overlayHolder);
} else {
if (numChildren > 0)
setChildIndex(overlayHolder, numChildren-1);
}
var g:Graphics = overlayHolder.graphics;
g.beginFill(0xFF0000, 0.5);
g.drawRect(0, 0, width, height);
g.endFill();
} else if (overlayHolder.parent == this) {
removeChild(overlayHolder);
}
}
Edit:可用于将叠加层添加到显示列表的一个属性是rawchildren http://livedocs.adobe.com/flex/3/langref/mx/core/Container.html#rawChildren:
package {
import flash.display.Graphics;
import flash.display.Sprite;
import mx.containers.VBox;
public class MyVBox extends VBox {
public var overlayEnabled : Boolean = true;
public var overlay : Sprite = new Sprite();
public function MyVBox() {
super();
}
protected override function updateDisplayList(unscaledWidth : Number, unscaledHeight : Number) : void {
super.updateDisplayList(unscaledWidth, unscaledHeight);
if (overlayEnabled) {
if (overlay.parent != this) {
rawChildren.addChild(overlay);
} else {
if (rawChildren.numChildren > 0)
rawChildren.setChildIndex(overlay, rawChildren.numChildren - 1);
}
var g : Graphics = overlay.graphics;
g.beginFill(0xFF0000, 0.5);
g.drawRect(0, 0, width, height);
g.endFill();
} else if (overlay.parent == this) {
rawChildren.removeChild(overlay);
}
}
}
}