apache-flex - 如何将控件添加到 flex 面板的标题栏？

Question

我试图通过在 Panel 控件的右上角添加一个句柄来实现一个可折叠的 TitleWindow 弹出窗口。不幸的是，我添加为 handle 的图像在绘制控件时没有显示。我可以通过更改图像的来源来触发重绘，所以显然它在那里，但它以某种方式隐藏了。

有没有办法让这个 Image 控件对用户可见？

这是窗口的代码:

package
{
    import mx.containers.Panel;
    import mx.controls.Image;

    public class CollapsableWindow extends Panel
    {
        public function CollapsableWindow()
        {
            super();
        }

        public var close:Image;

        protected override function createChildren():void
        {
            super.createChildren();
            close = new Image();
            close.source = "/assets/close.png";
            close.x = this.width - 20;
            close.y = 8;
            this.titleBar.addChildAt(close, 0);
        } 

    }
}

Answer 1

您需要在 createChildren 方法中创建按钮，然后将其放置在 updateDisplayList 方法中:

    /**
     * Creates the button and adds it to the titlebar
     */
    override protected function createChildren():void 
    {
        super.createChildren();

        this.myButton = new Button();
        this.myButton.addEventListener(MouseEvent.CLICK, onButtonClick);
        this.titleBar.addChild(this.myButton);
    }

    /**
     * Sizes and positions the button on the titlebar
     */
    override protected function updateDisplayList(unscaledWidth:Number, unscaledHeight:Number):void 
    {
        super.updateDisplayList(unscaledWidth, unscaledHeight);

        this.myButton.setActualSize(myButton.getExplicitOrMeasuredWidth(),
                                       myButton.getExplicitOrMeasuredHeight());

        // Position the button 
        var y:int = 4;
        var x:int = this.width - this.myButton.width - 2;
        this.myButton.move(x, y);
    }