通過AssetManager管理和加載資產（Libgdx）

Question

Im與Libgdx提供的AssetManager存在一些問題。 我得到一個空指針：

Java.lang.IllegalArgumentException：紋理不能爲null。

at com.badlogic.gdx.graphics.g2d.TextureRegion.<init>(TextureRegion.java) 
at com.test.test.screens.screens.MainScreen.show(MainScreen.java) 
at com.badlogic.gdx.Game.setScreen(Game.java) 
at com.test.test.screens.screens.SplashScreen.render(SplashScreen.java) 

從來就檢查和文件it's負荷存在，並且正確的，所以it's在我的代碼的東西。我實際上不知道該怎麼做。我被告知要確保我沒有創建一個新的資產實例，而是創建一個現有的實例。不知道是否從來就做到了，雖然正確.. 這是類它的自我：

public class Assets { 

    public final AssetManager manager = new AssetManager(); 
    private ObjectMap<String, Texture> textures; 
    private ObjectMap<String, Sound> sounds; 
    public final String background = "test.jpg"; 

public Assets() { 
    textures = new ObjectMap<String, Texture>(); 
    sounds = new ObjectMap<String, Sound>(); 
    manager.load(background, Texture.class); 

} 

public boolean update() { 
    boolean done = manager.update(); 
    if (done) { 
     finishLoading(); 

    } 
    return done; 
} 

private void finishLoading() { 
    textures.put(background, manager.get(background, Texture.class)); 

} 

public Texture getTexture(String name) { 
    return textures.get(name); 
} 
    public void dispose() { 

     manager.clear(); 

    } 
} 

而此刻我宣佈它像這樣在我MainClass：

public class MainClass extends Game { 
public SpriteBatch batch; 
public purchaseInterface pi; 
//Calls the Assets to be implemented in other classes 
public Assets assets; 
public MainClass(purchaseInterface purchase, GalleryOpener opener){ 
    this.gallery= opener; 
    this.pi = purchase; 
} 
@Override 
public void create() { 
    batch = new SpriteBatch(); 
    assets = new Assets(); 
    setScreen(new SplashScreen(this)); 
    } 

@Override 
public void resize(int width, int height) { 
    super.resize(width, height); 

} 

@Override 
public void render() { 
    super.render(); 


} 

@Override 
public void dispose() { 
    super.dispose(); 
    batch.dispose(); 
    assets.dispose(); 
} 

public Assets getAssets() { 
    return assets; 
} 


@Override 
public void pause() { 
    super.pause(); 
} 


@Override 
public void resume() { 
    // TODO Auto-generated method stub 
    super.resume(); 
} 

} 而用於裝載資產到屏幕類例如：

public Assets assets; 
public MainScreen(MainClass gam) { 
    game = gam; 
    assets = game.getAssets(); 
    loadStore(); 
    camera = new OrthographicCamera(screenWidth,screenHeight); 
    view = new StretchViewport(screenWidth, screenHeight, camera); 
    view.apply(); 
    camera.translate(camera.viewportWidth/2, camera.viewportHeight/2); 

} 

public void loadStore() { 
    background = assets.getTexture(assets.background); 
} 



@Override 
public void render(float delta) { 

    camera.update(); 

    game.batch.setProjectionMatrix(camera.combined); 

    game.batch.begin(); 

    game.batch.draw(background, 0, 0, 1000, 2000); 

    game.batch.end(); 

} 

@Override 
public void resize(int width, int height) { 
    view.update(width, height, true); 
} 

@Override 
public void show() { 
} 




@Override 
public void hide() { 
    // TODO Auto-generated method stub 

} 

@Override 
public void pause() { 
    // TODO Auto-generated method stub 

} 

@Override 
public void resume() { 
} 

@Override 
public void dispose() { 
    background.dispose(); 
} 

}

Answer 1

這不會加載背景紋理：

manager.load(background, Texture.class); 

您需要致電

manager.finishLoading(); 

負載（）來之後。 AssetManager.load（）只是存儲資產的路徑。 AssetManager.update（）從另一個線程的存儲路徑加載下一個項目，AssetManager.finishLoading（）加載所有項目並等待加載線程完成。當您想要在加載其他資源時繪製圖像時，需要首先加載該圖像（本例中爲「背景」）。

另一件事，我認爲你存儲的東西兩次沒有（紋理，聲音objectmaps）。最好的做法是使用資產管理器來獲取具有「獲取」功能的紋理或任何資產。

我這樣做：

public class LoadingScreen extends Screen { 

    ... 

    @Override 
    public void show() { 
     app.assets.load("data/textures/loading.pack", TextureAtlas.class); 
     app.assets.finishLoading(); // this is waits for the loading finish 

     app.assets.load("data/textures/menu.pack", TextureAtlas.class); 
     app.assets.load("data/textures/sprites.pack", TextureAtlas.class); 
     ... 

    } 

    @Override 
    public void render(float delta) { 
     if (app.assets.update()) { // this is loads the next item in an other thread 
      app.loadingFinished(); // this is where you will create the other screens 
     }    
     ... 
    } 

    ... 

「應用程序」 是一個遊戲實例， 「app.assets」 是AssetManager實例。當我想擁有一項資產時，我這樣做（但是這隻能在加載完成後運行！）：

TextureAtlas atlas = app.assets.get("data/textures/sprites.pack", TextureAtlas.class);