Question

更新：此帖子底部的解决方案。

我遇到的问题是，当我的游戏运行时，屏幕只是黑色并在几秒钟后崩溃。我在我的主Game类中声明了一个新的SpriteBatch：

public SpriteBatch batch;

我在Create method（）中实例化它并将整个Game类传递给名为Playscreen的Screen：

batch = new SpriteBatch();
setScreen(new PlayScreen(this));

在PlayScreen的构造函数中，我将传递的Game类设置为我设置的私有字段：

this.game = game;

这是我对PlayScreen的整个渲染方法：

@Override
public void render(float delta)
{
    update(delta);

    Gdx.gl.glClearColor(0, 2, 2, 1);
    Gdx.gl.glClear(GL20.GL_COLOR_BUFFER_BIT);

    game.batch.setProjectionMatrix(hud.stage.getCamera().combined);

    // Gdx.gl20.glActiveTexture(GL20.GL_TEXTURE0);

    game.batch.begin();
    for (Tile[] tileArray : tileMatrix.getTileMatrix())
    {
        for (Tile tile : tileArray)
        {
            tile.draw(game.batch);
        }
    }
    game.batch.end();

    hud.stage.draw();

}

tileArray是一个包含Tiles的二维数组。在我的create（）方法中，此数组中的每个tile都被初始化并分配了不同的位置。这是基类：

public abstract class Tile extends Sprite
{
    protected Texture texture;
    protected String name;
    protected int movementPoints;
    protected int foodYield;
    protected int productionYield;
    protected int tradeYield;

    public Tile(int mP, int fY, int pY, int tY, String name, Texture texture)
    {
        this.movementPoints = mP;
        this.foodYield = fY;
        this.productionYield = pY;
        this.tradeYield = tY;
        this.name = name;
        this.texture = texture;

        setBounds(0, 0, 50, 50);
    }

运行DesktopLauncher.java时，出现此错误：

Exception in thread "LWJGL Application" java.lang.NullPointerException
    at com.badlogic.gdx.graphics.g2d.SpriteBatch.flush(SpriteBatch.java:962)
    at com.badlogic.gdx.graphics.g2d.SpriteBatch.end(SpriteBatch.java:183)
    at com.marcusorciuch.reciv.screens.PlayScreen.render(PlayScreen.java:108)
    at com.badlogic.gdx.Game.render(Game.java:46)
    at com.marcusorciuch.reciv.ReCivMain.render(ReCivMain.java:47)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:225)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:126)

@

game.batch.end();

是的，我不知道发生了什么。

修改：对于遇到此问题的人，请确保您的班级来自Sprite，请务必致电super(texture)或Sprite 1}}你的类的部分内容不会被实例化。

Answer 1

当您设置并传递Game变量时，请使用final

final YourGame game; //final here

public PlayScreen(final YourGame game) { // final in the constructor declaration

发生SpriteBatch.end（）时出现java.lang.NullPointerException

1 个答案: