如何在LibGDX中为按钮创建“按下效果”

// 导入必要的类
import com.badlogic.gdx.Gdx;
import com.badlogic.gdx.graphics.Texture;
import com.badlogic.gdx.graphics.g2d.TextureRegion;
import com.badlogic.gdx.scenes.scene2d.InputEvent;
import com.badlogic.gdx.scenes.scene2d.Stage;
import com.badlogic.gdx.scenes.scene2d.ui.Button;
import com.badlogic.gdx.scenes.scene2d.ui.Skin;
import com.badlogic.gdx.scenes.scene2d.utils.ClickListener;

public class MyButtonScreen implements Screen {
    private Stage stage;
    private Button button;

    public void show() {
        stage = new Stage();
        Gdx.input.setInputProcessor(stage);

        // 创建按钮纹理
        Texture buttonTexture = new Texture("button.png");
        Texture buttonPressedTexture = new Texture("button_pressed.png");
        TextureRegion buttonRegion = new TextureRegion(buttonTexture);
        TextureRegion buttonPressedRegion = new TextureRegion(buttonPressedTexture);

        // 创建按钮样式
        Skin skin = new Skin();
        skin.add("default", buttonRegion);
        skin.add("pressed", buttonPressedRegion);

        // 创建按钮
        Button.ButtonStyle style = new Button.ButtonStyle();
        style.up = skin.getDrawable("default");
        style.down = skin.getDrawable("pressed");
        button = new Button(style);
        button.setPosition(100, 100);
        button.setSize(200, 100);

        // 添加按钮监听器
        button.addListener(new ClickListener() {
            @Override
            public void clicked(InputEvent event, float x, float y) {
                // 处理按钮点击事件
                System.out.println("Button clicked!");
            }
        });

        // 将按钮添加到舞台
        stage.addActor(button);
    }

    public void render(float delta) {
        Gdx.gl.glClearColor(0, 0, 0, 1);
        Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

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

    // 其他方法省略...

    public void dispose() {
        stage.dispose();
        buttonTexture.dispose();
        buttonPressedTexture.dispose();
        skin.dispose();
    }
}