Libgdx表行重叠？

Question

我是Libgdx的新手，刚开始用表格查看UI。我有一个textlabel（实际上是一个字体）和2个图像按钮。我喜欢一行中的字体和下面的两个按钮。我已经按照教程进行了操作，但似乎标签的行正在按钮行下方呈现。有谁知道为什么？

这是我的代码

public MainScreen() {
    spriteBatch = new SpriteBatch();
    stage = new Stage(Gdx.graphics.getWidth(), Gdx.graphics.getHeight(),
                      false, spriteBatch);

    //Create the text object that says "PennyPop"
    TextLabel pennyLabel = new TextLabel();
    //Create the sfx and api button button
    ImageButton sfxButton = createSfxButton();
    ImageButton apiButton = createApiButton();


     Gdx.input.setInputProcessor(stage);

     //Create the root table
     Table rootTable = new Table();
     rootTable.setFillParent(true);
     rootTable.debug();

     //Set up rows and columns
     table = new Table();
     table.add(pennyLabel);
     table.row();
     table.add(apiButton);
     table.add(sfxButton).padLeft(10);



     rootTable.add(table);                      
     stage.addActor(rootTable);

}

/ * ACTORS * /

 public class TextLabel extends Actor {
     float textWidth;   
     float textHeight;
        private BitmapFont font;

        public TextLabel(){
            font = new BitmapFont(Gdx.files.internal("assets/font.fnt"),
                                  false);
            textWidth = font.getBounds("PennyPop").width;
            textHeight = font.getBounds("PennyPop").height;

            font.setColor(Color.RED);

        }

        @Override
        public void draw(SpriteBatch batch, float parentAlpha) {
             font.draw(batch, "Pennypop", (stage.getWidth()-textWidth)/2,
                                       (stage.getHeight()-textHeight)/2);
             //Also remember that an actor uses local coordinates
             // for drawing within
             //itself!
        }
 }

 public ImageButton createSfxButton(){

            ImageButton sfxButton;

            buttonsUi = new TextureAtlas("assets/buttons/buttons.pack");
            Skin buttonSkin = new Skin(buttonsUi);

            ImageButtonStyle ButtonStyle = new ImageButtonStyle();
            //Set image for not pressed  
            ButtonStyle.up = buttonSkin.getDrawable("sfxButton"); 
            //Set image for pressed
            ButtonStyle.down = buttonSkin.getDrawable("apiButton");  
            ButtonStyle.pressedOffsetX = 1; 
            ButtonStyle.pressedOffsetY = -1;

            sfxButton = new ImageButton(ButtonStyle);
                sfxButton.setBounds(0, 0, 200, 200);

            //Initialize Sound Effect
             final Sound wavSound = Gdx.audio.newSound(Gdx.files.internal(
                                     "assets/button_click.wav"));

              sfxButton.addListener(new ClickListener(){
                    @Override 
                    public void clicked(InputEvent event, float x, float y){
                        wavSound.play();                       
                    }
                });


            return sfxButton;

 }

 public ImageButton createApiButton(){

        ImageButton apiButton;

        buttonsUi = new TextureAtlas("assets/buttons/buttons.pack");
        Skin buttonSkin = new Skin(buttonsUi);

        ImageButtonStyle ButtonStyle = new ImageButtonStyle(); 
        //Set image for not pressed 
        ButtonStyle.up = buttonSkin.getDrawable("apiButton");  
        //Set image for pressed
        ButtonStyle.down = buttonSkin.getDrawable("sfxButton");  
        ButtonStyle.pressedOffsetX = 1; 
        ButtonStyle.pressedOffsetY = -1;

        apiButton = new ImageButton(ButtonStyle);

          apiButton.addListener(new ClickListener(){

              //Fetch the weather api and add it to the stage
                @Override 
                public void clicked(InputEvent event, float x, float y){
                    WeatherReport weatherReport = new WeatherReport();
                }
            });


        return apiButton;

 }