使用AssetManager在Java libgdx上出错

因此，我开始尝试使用libgdx在java中进行一些游戏，并尝试使用AssetManager。但它总是出错。我将输入代码（我将尝试恢复代码）和输出。 游戏很好地通过了加载屏幕，但当它到达游戏屏幕时，它停止并给出了一个错误，我相信这是因为资产。 如果有人知道我为什么会犯这个错误

DesktopLauncher.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

按me.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

加载屏幕.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

GameScreen.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

Assets.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

AssetManager.java

public class DesktopLauncher {
    public static void main (String[] arg) {
        LwjglApplicationConfiguration config = new LwjglApplicationConfiguration();
        new LwjglApplication(new pressme(), config);
    }
}

public class pressme extends Game {

    LoadingScreen loadingscreen;
    AssetsManager assetsmanager;
    Assets assets;


    @Override
    public void create() {
        assets = new Assets();
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        assets.other();
        loadingscreen = new LoadingScreen(this);
        setScreen(loadingscreen);       
    }
}

public class LoadingScreen implements Screen {

    Assets assets;
    AssetsManager assetsmanager;
    private final pressme game;
    public GameScreen game_screen;

    public LoadingScreen(final pressme game){

        assets = new Assets();
        assetsmanager = new AssetsManager();
        this.game = game;

    }
    @Override
    public void show() {
        assetsmanager.load();

    }

    private void update(float delta){

        System.out.println(progress);
        if(assetsmanager.manager.update()) {
            game.setScreen(new GameScreen(game));
          }
        progress = assetsmanager.manager.getProgress();     
    }

}

public class GameScreen implements Screen {
    pressme game;
    Assets assets;
    AssetsManager assetsmanager;

    public GameScreen(pressme game){
        this.game = game;
        assets = new Assets();
        assetsmanager = new AssetsManager();
    }
    @Override
    public void render(float delta) { 

    Gdx.gl.glClearColor( 0.5F, 0.5F, 0.5F, 0.5F);
        Gdx.gl.glClear( GL20.GL_COLOR_BUFFER_BIT | GL20.GL_DEPTH_BUFFER_BIT );


        camera.update();
        generalUpdate(touch, camera);

        batch.setProjectionMatrix(camera.combined);
        assets.load();
        batch.begin();
        batch.draw(assets.back, 0, 0);
        batch.end();
   }


 }

public class Assets {

    AssetsManager assetsmanager;

    public Sprite back;

    public void load(){
        assetsmanager = new AssetsManager();
        assetsmanager.load();
        back = new Sprite(assetsmanager.manager.get(assetsmanager.back, Texture.class));
    }
}

public class AssetsManager {

    public AssetManager manager = new AssetManager();

    public String back  = "back.png";

    public void load(){

    manager.load(back, Texture.class);

    }
}

---

输出

LOADINGGG
0.0 

0.0 

0.015151516 

0.015151516 

0.030303031 

    .
    .
    .
0.969697 

0.9848485 

0.9848485 

Exception in thread "LWJGL Application" java.lang.NullPointerException

     at com.badlogic.gdx.graphics.g2d.SpriteBatch.draw(SpriteBatch.java:586)

     at com.david.pressme.GameScreen.render(GameScreen.java:244)

     at com.badlogic.gdx.Game.render(Game.java:46)

     at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:223)

     at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:124)

---

编辑

谢谢你的提示

因此，在我将“assets.load（）”放入后，仍然存在一些错误。我不知道“assets.load（）”是否在正确的位置

LOADINGGG
0.0
0.0
0.015151516
0.015151516
0.030303031
.
.
.
0.969697
0.969697
0.9848485
0.9848485
Exception in thread "LWJGL Application" com.badlogic.gdx.utils.GdxRuntimeException: Asset not loaded: back.png
    at com.badlogic.gdx.assets.AssetManager.get(AssetManager.java:144)
    at com.david.pressme.Assets.load(Assets.java:254)
    at com.david.pressme.GameScreen.render(GameScreen.java:172)
    at com.badlogic.gdx.Game.render(Game.java:46)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication.mainLoop(LwjglApplication.java:223)
    at com.badlogic.gdx.backends.lwjgl.LwjglApplication$1.run(LwjglApplication.java:124)

EDIT2

RC，Spylot，Tip，这是你说的

所以它解决了，我说

"assets.load" on "public void show()" 

这样，当屏幕加载时，他在开始时加载资产，我将其从屏幕上取下

"public void render(){" 

因为他总是加载资产，因为这是一个循环（我想是的），然后继续

"Assets.java public load(){" i put "assetsmanager.load();"

谢谢你的提示。然后在同一个地方我把

"assetsmanager.manager.finishLoading();"

因此，它在执行某项操作之前加载所有资产。谢谢你给我的小费

---

非常感谢所有帮助或试图帮助您的人。

您应该知道，在加载资产时，在调用finishLoading之前，您无法使用这些资产。finishLoading阻止所有试图抓住资源的调用，直到它们在内存中完全加载

我强烈建议你读这本书

---

因此，简而言之，每次使用load（）调用后，应该使用

manager.finishLoading（）

完成它。问题最有可能是因为

Assets#back

为null（因为

Assets#load（）

从未调用过），并且很难提取null，因此在“batch.begin（）”之前添加“Assets.load”（我不知道这是否是放置它的正确位置），但给了我一个错误，我将编辑postYeah，因为它显然与AssetManager相同（未调用load），也许您应该花时间阅读文档和一些教程。我想问题在于路径名。在路径中添加文件夹名，如“data/back.png”@RC，我想当我调用“assets.load（）”时，它也会调用“assetsmanager.load（）”，因为在assets.load上有一个assetmanager.load（）->

public void load（）{assetsmanager=new assetsmanager（）；assetsmanager.load（））

虽然这似乎是一个很好的答案，但您应该简短地描述问题所在以及完成加载的内容do@m.antkowicz我希望现在能令人满意。：）但如果我使用“finishLoading”，我认为加载屏幕不会工作，因为只有在加载所有资产后才会显示。加载屏幕的目的是在加载资产时显示，并显示process@DavidBorges事实上，在使用finishLoading之前，您无法访问正在加载的资产。您必须通过1）使用update（）来解决这一问题；一旦它返回true，您将切换状态（但这可能会很快变亮）2）您创建一个独立于AssetManager的加载屏幕（也就是说，您在其他地方将其作为公共静态启动），并设置一个计时器，在几秒钟后，触发update（）或切换状态。@LoadingScreen.java上的Spylot我正在使用此“**如果（assetsmanager.manager.update（）{game.setScreen（newgamescreen（game））；}**”，这不是你说的吗？