情况:
首先，我是 LibGDX 的新手。

我正在制作一款玩家可以在屏幕上看到所有成就的游戏，因此我为此使用了ScrollPane。

成就以弹出的形式显示(见下图)。成就列表将在这些红线内。

屏幕截图:

问题:
问题是:当我将小部件添加到 ScrollPane 时，屏幕只显示黑屏。

奇怪的是:
- 当我拖动 ScrollPane 时，所有内容都正确呈现。
- 但是当我放手时，屏幕再次变黑。

我做了什么:
- 我发现我放在ScrollPane 参数 中的任何 Actor (不仅仅是表格)都会导致黑屏。
- 如果我将它设置为 null，它工作正常。

代码:

public void show() {
    stage = new Stage();

    roomScreenUI = new RoomScreenUI();
    roomScreenUI.setName("RoomScreenUI");
    stage.addActor(roomScreenUI);

    roomScreenButton = new RoomScreenButton[5];
    for(int i=0; i<roomScreenButton.length; i++){
        roomScreenButton[i] = new RoomScreenButton(i+1, roomScreenUI.getScaleFactor());
        roomScreenButton[i].setName("RoomScreenButton");
        stage.addActor(roomScreenButton[i]);
    }

    roomScreenAchievementUI = new RoomScreenAchievementUI(roomScreenUI.getScaleFactor());
    roomScreenAchievementUI.setName("RoomScreenAchievementUI");
    stage.addActor(roomScreenAchievementUI);


    //----------------THE PROBLEM LIES HERE----------------//

    achievementContainer = new Table();

    scrollPane = new ScrollPane(achievementContainer);
    // scrollPane = new ScrollPane(null); <-- If I replace it with this line, it works fine

    //----------------THE PROBLEM LIES HERE----------------//

    achievementTable = new Table();
    achievementTable.setSize(roomScreenAchievementUI.getWidth() * 0.9f, roomScreenAchievementUI.getHeight() * 0.8f);
    achievementTable.setPosition(roomScreenAchievementUI.getX() + roomScreenAchievementUI.getWidth() / 2 - achievementTable.getWidth() / 2, roomScreenAchievementUI.getY() + roomScreenAchievementUI.getHeight() * 0.48f - achievementTable.getHeight() / 2);
    achievementTable.debug();
    achievementTable.add(scrollPane).expand().fill();
    achievementTable.setName("AchievementTable");
    stage.addActor(achievementTable);

    Gdx.input.setInputProcessor(stage);
}

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

    // ... code omitted ... //

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

问题:
任何人对发生的事情有任何想法吗？
我该如何解决？
提前致谢...

============================================ ====================================== 更新 =============================================== ===================================
经过几个小时的实验，我从头开始创建了一个只有屏幕和 Actor 的简单得多的项目:

TestActor.java(这是 Actor )

Texture texture;
Sprite sprite;

public TestActor(){
    // I used the default generated image badlogic.jpg
    texture = new Texture(Gdx.files.internal("badlogic.jpg"));
    sprite = new Sprite(texture);
}

@Override
public void draw(Batch batch, float alpha){
    batch.draw(sprite, 0, 0, Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
}

TestClass.java(这是屏幕)

Stage stage;
ScrollPane scrollPane;
Table outerTable, innerTable;
TestActor testActor;

@Override
public void show() {
    stage = new Stage();

    testActor = new TestActor();
    stage.addActor(testActor);

    //---------THE PROBLEM IS STILL HERE---------//

    innerTable = new Table();
    scrollPane = new ScrollPane(innerTable); // change it to null, it works

    //---------THE PROBLEM IS STILL HERE---------//

    outerTable = new Table();
    outerTable.setPosition(0, 0);
    outerTable.setSize(Gdx.graphics.getWidth(), Gdx.graphics.getHeight());
    outerTable.debug();
    outerTable.add(scrollPane).fill().expand();
    stage.addActor(outerTable);
}

@Override
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();
}

Also I figured out something that may be a clue while I was debugging:
- At the first frame, everything is rendered properly.
- Starting from second frame, the screen goes black.

这是一个错误吗？
还是我理解有误？
任何帮助将不胜感激...

最佳答案

对于仍然遇到此错误的人，这是一种解决方法:尝试 scrollpane.setFadeScrollBars(false);

关于java - LibGDX ScrollPane 显示黑屏，我们在Stack Overflow上找到一个类似的问题： https://stackoverflow.com/questions/27539112/