LibGDX Label Not Drawing

我試圖在屏幕上爲我的遊戲的幫助屏幕繪製一個LibGDX標籤，但是，我沒有從JVM中得到任何錯誤，但是標籤文本不會繪製。LibGDX Label Not Drawing

這是我HelpMenu類：

package metrovelox.screens; 

//imports... 
public class HelpMenu extends Screen { 

    private Stage stage; 

    public HelpMenu(Game game, String name) { 
     super(game, name); 
    } 

    @Override 
    public void init() { 
     Texture.setEnforcePotImages(false); 

     stage = new Stage(); 

     Group background = new Group(); 
     Group foreground = new Group(); 

     background.setBounds(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); 
     foreground.setBounds(0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight()); 

     stage.addActor(background); 
     stage.addActor(foreground); 

     background.addActor(ResourceLoader.loadImage("ui/Main Menu Background.jpg")); 

     TextButton back = new TextButton("back", GuiSkinRegistry.retrieve("Simple Buttons")); 
     back.setPosition(Utils.getScreenCenter().x - 186, Utils.getScreenCenter().y - 200); 

     Label text = new Label("Hello", GuiSkinRegistry.retrieve("Simple Label")); 
     text.setPosition(Utils.getScreenCenter().x, Utils.getScreenCenter().y); 

     back.addListener(new ClickListener(Buttons.LEFT) { 
      @Override 
      public void clicked(InputEvent event, float x, float y) { 
       getGame().setScreen(getGame().getScreen("Main Menu")); 
      } 
     }); 

     foreground.addActor(back); 
     foreground.addActor(text); 

     Gdx.input.setInputProcessor(stage); 
    } 

    @Override 
    public void render(float delta) { 
     super.render(delta); 
     stage.act(delta); 
     stage.draw(); 
    } 

    @Override 
    public void dispose() { 
     super.dispose(); 
     stage.dispose(); 
    } 

}

這是我主要的遊戲類：

package metrovelox.core; 

import metrovelox.screens.HelpMenu; 
import metrovelox.screens.MainMenu; 

public class Metrovelox extends Game { 

    @Override 
    public void init() { 
     //Register skins, screens etc... 
     GuiSkinRegistry.register("Simple Buttons", ResourceLoader.loadSkin("MainMenu", ResourceLoader.loadTextureAtlas("ui/simple_buttons"))); 
     GuiSkinRegistry.register("Simple Label", ResourceLoader.loadSkin("HelpMenu")); 

     addScreen(new MainMenu(this, "Main Menu")); 
     addScreen(new HelpMenu(this, "Help Menu")); 


     setScreen(getScreen("Main Menu")); 
    } 

}

這是我的皮膚文件：

{ 
    com.badlogic.gdx.graphics.Color: { 
     white: { hex: "ffffff" } 
    }, 
    com.badlogic.gdx.graphics.g2d.BitmapFont: { 
     impact: {file: "../fonts/impact.fnt"} 
    }, 
    com.badlogic.gdx.scenes.scene2d.ui.Label$LabelStyle: { 
     default: { 
      font: impact, fontColor: white 
     } 
    } 
}

這是一個屏幕截圖幫助屏幕： Screenshot