如何让我的角色在 Actionscript 3.0 中沿对角线移动

Question

我无法使用箭头键使我的人物沿对角线移动。我可以让它向上、向下、向左、向右移动，但我不确定如何让它读取两个按钮同时按下，因此它应该以某种方式移动。这是迄今为止我所拥有的按键代码。任何提示表示赞赏！

function keyPressHandler(event:KeyboardEvent):void
    {
        switch( event.keyCode )
        {
            case Keyboard.UP:
                up = true;
                beetle_mc.rotation = 0;
                beetle_mc.y -=speed;
                up_mc.gotoAndStop(2);
                break;
                
            case Keyboard.DOWN:
                down = true;
                beetle_mc.rotation = 180;
                beetle_mc.y +=speed;
                down_mc.gotoAndStop(2);
                break;
                
            case Keyboard.LEFT:
                left = true;
                beetle_mc.rotation = 270;
                beetle_mc.x -=speed;
                left_mc.gotoAndStop(2);
                break;
                
            case Keyboard.RIGHT:
                right = true;
                beetle_mc.rotation = 90;
                beetle_mc.x +=speed;
                right_mc.gotoAndStop(2);
                break;