如何修复 libgdx 中的屏幕无渲染

Question

我对 libgdx 有点陌生，我试图为我的游戏制作一个主菜单，但是当我打开它时它只是一个黑屏

这就是 MyGdxGame class

import com.badlogic.gdx.*;

public class MyGdxGame extends Game
{
    @Override
    public void create() {
    setScreen(new MenuScreen());
    }

    
}

这就是菜单屏幕 class

import com.badlogic.gdx.*;
import com.badlogic.gdx.graphics.*;
import com.badlogic.gdx.graphics.g2d.*;
import com.badlogic.gdx.scenes.scene2d.*;
import com.badlogic.gdx.scenes.scene2d.ui.*;
import com.badlogic.gdx.scenes.scene2d.utils.*;
import com.badlogic.gdx.utils.viewport.*;
import com.mycompany.mygame.*;
import com.badlogic.gdx.scenes.scene2d.ui.TextButton.*;

public class LoadingScreen implements Screen{

    private SpriteBatch batch;
    protected Stage stage;
    private Viewport viewport;
    private OrthographicCamera camera;
    BitmapFont font = new BitmapFont();
    Skin skinButton = new Skin();
    TextureAtlas buttonAtlas = new TextureAtlas("buttons/button.txt");
    

    private TextButton.TextButtonStyle textButtonStyle;

    public LoadingScreen()
    {
        skinButton.addRegions(buttonAtlas);
        textButtonStyle = new TextButton.TextButtonStyle();
        textButtonStyle.font = font;

        textButtonStyle.up = skinButton.getDrawable("rounded_rectangle_button");
        textButtonStyle.down = skinButton.getDrawable("rounded_rectangle_button");
        textButtonStyle.checked = skinButton.getDrawable("rounded_rectangle_button");
        
        batch = new SpriteBatch();
        camera = new OrthographicCamera();
        viewport = new FitViewport(camera.viewportWidth, camera.viewportHeight, camera);
        viewport.apply();

        camera.position.set(camera.viewportWidth / 2, camera.viewportHeight / 2, 0);
        camera.update();

        stage = new Stage(viewport, batch);    
    }


    @Override
    public void show() {
        //Stage should controll input:
        Gdx.input.setInputProcessor(stage);

        //Create Table
        Table mainTable = new Table();
        //Set table to fill stage
        mainTable.setFillParent(true);
        //Set alignment of contents in the table.
        mainTable.top();

        //Create buttons
        TextButton playButton = new TextButton("Play", textButtonStyle);
        TextButton optionsButton = new TextButton("Options", textButtonStyle);
        TextButton exitButton = new TextButton("Exit", textButtonStyle);

        //Add listeners to buttons
        playButton.addListener(new ClickListener(){
                @Override
                public void clicked(InputEvent event, float x, float y) {
                    ((Game)Gdx.app.getApplicationListener()).setScreen(new PlayScreen());
                }
            });
        exitButton.addListener(new ClickListener(){
                @Override
                public void clicked(InputEvent event, float x, float y) {
                    Gdx.app.exit();
                }
            });

        //Add buttons to table
        mainTable.add(playButton);
        mainTable.row();
        mainTable.add(optionsButton);
        mainTable.row();
        mainTable.add(exitButton);

        //Add table to stage
        stage.addActor(mainTable);
    }

    @Override
    public void render(float delta) {
        Gdx.gl.glClearColor(.1f, .12f, .16f, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

        stage.act();
        stage.draw();
    }

    @Override
    public void resize(int width, int height) {
        viewport.update(width, height);
        camera.position.set(camera.viewportWidth / 2, camera.viewportHeight / 2, 0);
        camera.update();
    }

    @Override
    public void pause() {

    }

    @Override
    public void resume() {

    }

    @Override
    public void hide() {

    }

    @Override
    public void dispose() {
        buttonAtlas.dispose();
        font.dispose();
        skinButton.dispose();
        buttonAtlas.dispose();
        batch.dispose();
    }
}

这是 button.txt 文件

button.png
format: RGBA8888
filter: Linear,Linear
repeat: none
rounded_rectangle_button
  rotate: false
  xy: 2, 2
  size: 256, 108
  orig: 256, 128
  offset: 0, 10
  index: -1

button.png 与 assets/buttons 中的 button.txt 在同一个文件中它根本不会抛出任何异常