Question

这可能很简单，但我无法弄明白。看看代码，我将这个按钮类（CategoryButton）的2个实例移动到舞台上。正如您所看到的，当您单击按钮时，它应该转到右侧播放（3），将其自身记录为selectedBtn。单击第二个按钮时，应重新启用第一个按钮的侦听器，删除自身的侦听器并将其自身设置为新选择的按钮。不幸的是，这段代码并没有这样做。当我点击第一个按钮时，它将按钮移动到第3帧，并删除其听众。我单击第二个按钮，它会执行相同的操作，但它不会再次为第一个按钮添加侦听器。

我是AS3的新手，非常感谢任何帮助，谢谢。

package classes {
    import flash.events.MouseEvent;
    import flash.display.MovieClip;
    import flash.display.Sprite;

    public class CategoryButton extends MovieClip{

        //this stores the currently selected button
        public var selectedBtn:Object;

        public function CategoryButton() {
            // listen for over
            addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);

        }

        protected function rolloverToggle(event:MouseEvent):void {
            gotoAndStop(2);
            removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
            addEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
            addEventListener(MouseEvent.CLICK, buttonToggle);
        }

        protected function rolloutToggle(event:MouseEvent):void {
            gotoAndStop(1);
            removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
            addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
        }

        protected function buttonToggle(event:MouseEvent):void {
            if(selectedBtn) {
                trace(selectedBtn.name)
                selectedBtn.addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
                selectedBtn.gotoAndStop(1);

                event.currentTarget.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
                event.currentTarget.removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
                event.currentTarget.removeEventListener(MouseEvent.CLICK, buttonToggle);

                event.currentTarget.gotoAndStop(3);

                selectedBtn = event.currentTarget;
            }else {

                selectedBtn = event.currentTarget;
                trace(selectedBtn.name);
                selectedBtn.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
                selectedBtn.removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
                selectedBtn.removeEventListener(MouseEvent.CLICK, buttonToggle);

                selectedBtn.gotoAndStop(3);
            }
        }

    }

}

Answer 1

我自己并不熟悉AS3，但是当您尝试对selectedBtn对象if(selectedBtn)进行布尔测试时，可能会出现问题。为什么不使用诸如“is_selected_button”之类的成员变量来跟踪按钮状态，然后在if语句中测试该变量，而不是针对Object进行测试。

Answer 2

我如何修理它：

单击按钮A（A设置为selectedBtn，禁用侦听器，状态更改为第3帧）
单击按钮B（selectedBtn的侦听器重置，状态更改，selectedBtn设置为按钮B）

这就是问题所在，A的听众设置如下：

addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);

这导致Button B再次活跃起来。解决方法是简单地将侦听器更改为currentTarget以及gotoAndStop，用于over和out状态。

event.currentTarget.gotoAndStop(1);
event.currentTarget.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);


package classes {
import flash.events.MouseEvent;
import flash.display.MovieClip;
import flash.display.Sprite;

public class CategoryButton extends MovieClip{

    //this stores the currently selected button
    public static var selectedBtn:Object;

    public function CategoryButton() {
        // listen for over
        addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
        trace("called");

    }

    protected function rolloverToggle(event:MouseEvent):void {
        event.currentTarget.gotoAndStop(2);
        event.currentTarget.removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
        event.currentTarget.addEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
        event.currentTarget.addEventListener(MouseEvent.CLICK, buttonToggle);
    }

    protected function rolloutToggle(event:MouseEvent):void {
        event.currentTarget.gotoAndStop(1);
        event.currentTarget.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
        event.currentTarget.addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
    }

    protected function buttonToggle(event:MouseEvent):void {
        if(selectedBtn) {
            trace(selectedBtn.name);
            selectedBtn.addEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
            selectedBtn.gotoAndStop(1);

            event.currentTarget.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
            event.currentTarget.removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
            event.currentTarget.removeEventListener(MouseEvent.CLICK, buttonToggle);

            event.currentTarget.gotoAndStop(3);

            selectedBtn = event.currentTarget;
        }else {

            selectedBtn = event.currentTarget;
            selectedBtn.removeEventListener(MouseEvent.MOUSE_OUT, rolloutToggle);
            selectedBtn.removeEventListener(MouseEvent.MOUSE_OVER, rolloverToggle);
            selectedBtn.removeEventListener(MouseEvent.CLICK, buttonToggle);

            selectedBtn.gotoAndStop(3);

        }
    }

}

}

Flash Actionscript 3打开/关闭菜单按钮

2 个答案: