在类 AS3 之间传递对象引用

Question

制作地图创建程序。 Field.as 实例化 _player。 Player.as 将Child _editorPanel 添加到父级。当我单击编辑器面板中的按钮时，EditorPanel.as 会实例化一个名为 tilepalette 的影片剪辑。 Tilepalette 包含我希望能够通过单击我想要的图块从中选择一个图块的所有图块集。

Field.as:

package  {

    import flash.display.MovieClip;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.events.MouseEvent;
    import flash.display.BitmapData;
    import flash.display.Bitmap;
    import flash.display.FrameLabel;
    import flash.display.DisplayObjectContainer;
    import flash.geom.Rectangle;

    public class Field extends MovieClip{

        private var player:Player;
        private var sampleTile:Tile = new Tile();
        private var _tilePalette:TilePalette;
        private var _paletteArray:Array = [];

        public function Field() 
        {
            player = new Player();
            player.x = 0;
            player.y = 0;
            addChild(player);

            GetSampleTiles();
        }

        private function GetSampleTiles()
        {
            for (var i:int = 1; i <= sampleTile.totalFrames; i++)
            {
                var tileObj:Object = new Object();

                sampleTile.gotoAndStop(i);

                var graphicData:BitmapData = new BitmapData(32,32);
                graphicData.draw(sampleTile);

                tileObj.Name = sampleTile.currentFrameLabel;
                tileObj.Graphic = graphicData;
                tileObj.Frame = sampleTile.currentFrame;

                Engine._tilesData.push(tileObj);
            }
        }
    }
}

Player.as：

package  {

    import flash.display.MovieClip;
    import flash.events.Event;
    import flash.events.KeyboardEvent;
    import flash.events.MouseEvent;
    import flash.display.BitmapData;
    import flash.display.Bitmap;


    public class Player extends MovieClip 
    {
        private var _inp:Input = new Input();
        private var _playerXindex:int = 0;
        private var _playerYindex:int = 0;
        private var _heldTile:Object;
        private var _editorPanel:EditorPanel;

        public function Player() 
        {
            addChild(_inp);
            addEventListener(Event.ENTER_FRAME, HandleKeys);

            _heldTile = new Object();
        }

        private function HandleKeys(e:Event)
        {
            _playerXindex = x/32;
            _playerYindex = y/32;

            if(_inp.keyUp)
            {
                y -= 32;
            }
            if(_inp.keyDown)
            {
                y += 32;
            }
            if(_inp.keyLeft)
            {
                x -= 32;
            }
            if(_inp.keyRight)
            {
                x += 32;
            }
            if(_inp.keySpace)
            {
                try{DrawATile(_heldTile);}
                catch(err:Error){trace("Bad or no graphic. Using this instead.");}
                finally{DrawATile(Engine._tilesData[0]);}
            }
            if(_inp.keyA)
            {
                trace(Engine.tileObjIndex[_playerYindex][_playerXindex].Name);
            }
            if(_inp.keyB)
            {
                BuildStarterIndex();
                SetHeldTile(Engine._tilesData[0]);
            }
        }

        private function DrawATile(tileToDraw:Object)
        {
            if (Engine.tileObjIndex[_playerYindex][_playerXindex].Name.indexOf("Placeholder") >= 0)
            {
                trace("set");
                var graphicData:BitmapData = new BitmapData(32,32);
                graphicData.draw(tileToDraw.Graphic);

                Engine.tileObjIndex[_playerYindex][_playerXindex].Name = tileToDraw.Name;
                Engine.tileObjIndex[_playerYindex][_playerXindex].Graphic = tileToDraw.Graphic;

                var newTile:Bitmap = new Bitmap(tileToDraw.Graphic);
                newTile.x = x;
                newTile.y = y;
                parent.addChild(newTile);
            }
        }

        private function BuildStarterIndex()
        {
            _editorPanel = new EditorPanel();
            _editorPanel.x = 1;
            _editorPanel.y = 544;
            parent.addChild(_editorPanel);

            for (var i:int = 0; i < 20; i++)
            {
                Engine.tileObjIndex[i] = [];

                for (var u:int = 0; u < 20; u++)
                {
                    var tileObj:Object = new Object();

                    var graphicData:BitmapData = new BitmapData(32,32);
                    graphicData.draw(Engine._tilesData[0].Graphic);

                    tileObj.Name = "Placeholder" + "["+i+"]"+"["+u+"]";
                    tileObj.Graphic = graphicData;
                    tileObj.Frame = 0;

                    Engine.tileObjIndex[i].push(tileObj);
                }
            }
        }

        private function SetHeldTile(tiletoset:Object)
        {
            _heldTile.Name = tiletoset.Name;
            _heldTile.Graphic = tiletoset.Graphic;
            _heldTile.Frame = tiletoset.Frame;

            _editorPanel.tileName.text = _heldTile.Name;
            _editorPanel.tileFrame.text = _heldTile.Frame;

            var heldTile:Bitmap = new Bitmap(_heldTile.Graphic);
            heldTile.x = 30;
            heldTile.y = 31;
            _editorPanel.addChild(heldTile);
        }
    }
}

EditorPanel.as：

package  {

    import flash.display.MovieClip;
    import flash.events.MouseEvent;
    import flash.display.Bitmap;
    import flash.events.Event;

    public class EditorPanel extends MovieClip
    {
        public var _tilePalette:TilePalette;
        private var _pArray:Array = [];
        private var _mouseXi:int;
        private var _mouseYi:int;
        public var _tileGrabbed:Object;

        public function EditorPanel() 
        {
            btnpalette.addEventListener(MouseEvent.CLICK, BuildPalette);
        }

        private function UpdateMouse(e:Event)
        {
            _mouseXi = Math.floor(_tilePalette.mouseX/32);
            _mouseYi = Math.floor(_tilePalette.mouseY/32);
        }

        private function BuildPalette(e:MouseEvent)
        {
            _tilePalette = new TilePalette();
            _tilePalette.x = mouseX;
            _tilePalette.y = mouseY-256;
            addChild(_tilePalette);
            var counter:int = 1;

            for (var i:int = 0; i < 8; i++)
            {
                _pArray[i] = [];
                for(var u:int = 0; u < 8; u++)
                {
                    if(counter >= Engine._tilesData.length)
                    {
                        counter = 1;
                    }
                    var b:Bitmap = new Bitmap(Engine._tilesData[counter].Graphic);
                    b.x = 32 * u;
                    b.y = 32 * i;
                    _tilePalette.addChild(b);

                    _pArray[i].push(Engine._tilesData[counter]);
                    counter++;
                }
            }
            _tilePalette.addEventListener(MouseEvent.MOUSE_MOVE, UpdateMouse);
            _tilePalette.addEventListener(MouseEvent.CLICK, GrabATile);
        }

        private function GrabATile(e:MouseEvent)
        {
            return _pArray[_mouseXi][_mouseYi];
        }
    }
}

问题是当我做 GrabATile 时，我不知道如何处理返回的 Object 引用。我想在 Player 函数 SetHeldTile 中使用该对象。

Answer 1

所以这将使它工作，但我建议稍微重构一下该代码。添加向他们的父母添加东西的孩子不是最好的设计......那里还有循环赛的东西，编辑器选择瓷砖，但是玩家在被告知后将像tileName这样的东西设置回编辑器新瓷砖。这应该发生在发生平铺选择等的编辑器中。

也就是说，根据您的流程，以下是如何使其工作：

EditorPanel 已经有一个属性 _tileGrabbed。所以在你的 GrabATile() 方法中只需设置

_tileGrabbed = _pArray[_mouseXi][_mouseYi];

然后在你的 setHeldTile() 方法中......简单地说

_heldTile = _editorPanel._tileGrabbed.  

现在，如果您需要 GrabATile() 来触发 setHeldTile()，最好的处理方法是使用事件。

// in EditorPanel

private function GrabATile(e:MouseEvent){
    _tileGrabbed =  _pArray[_mouseXi][_mouseYi];
    dispatchEvent(new Event("tileChanged"));
}

// in Player

private function BuildStarterIndex(){
    _editorPanel = new EditorPanel();
    _editorPanel.addEventListener("tileChanged", setHeldTile);
    // ... rest of code
}

private function SetHeldTile(event:Event){
    _heldTile = _editorPanel._tileGrabbed;
    // ... rest of code
}