尝试从空对象引用上的字段“GlyphRun.color”中读取答案

【问题标题】：Attempt to read from field 'GlyphRun.color' on a null object reference尝试从空对象引用上的字段“GlyphRun.color”中读取
【发布时间】：2017-07-14 13:21:32
【问题描述】：

我一直在努力让字体与 libgdx 一起工作，我终于做到了。

但现在它抛出了一个异常，我无法弄清楚。

java.lang.NullPointerException: Attempt to read from field 'com.badlogic.gdx.graphics.Color com.badlogic.gdx.graphics.g2d.GlyphLayout$GlyphRun.color' on a null object reference
  at com.badlogic.gdx.graphics.g2d.GlyphLayout.setText(GlyphLayout.java:141)
  at com.badlogic.gdx.graphics.g2d.BitmapFontCache.addText(BitmapFontCache.java:505)
  at com.badlogic.gdx.graphics.g2d.BitmapFontCache.addText(BitmapFontCache.java:487)
  at com.badlogic.gdx.graphics.g2d.BitmapFontCache.setText(BitmapFontCache.java:438)
  at yt.agar.game.Screens.GameScreen.render(GameScreen.java:213)
  at com.badlogic.gdx.Game.render(Game.java:46)
  at com.badlogic.gdx.backends.android.AndroidGraphics.onDrawFrame(AndroidGraphics.java:459)
  at android.opengl.GLSurfaceView$GLThread.guardedRun(GLSurfaceView.java:1522)
  at android.opengl.GLSurfaceView$GLThread.run(GLSurfaceView.java:1239)

字形布局.java:141: https://github.com/libgdx/libgdx/blob/master/gdx/src/com/badlogic/gdx/graphics/g2d/GlyphLayout.java#L141

我是这样画字体的：

BitmapFont font = assetManager.get('arial-96.otf');
font.draw(spriteBatch, "sample text", 10, 10);

我以这种方式生成位图字体，使用AssetManager。我尝试了很多不同的字体，包括 truetype 字体。

FreetypeFontLoader.FreeTypeFontLoaderParameter font = new FreetypeFontLoader.FreeTypeFontLoaderParameter();
font.fontFileName = "fonts/arial.otf";
font.fontParameters.color = Color.WHITE;
font.fontParameters.borderColor = Color.BLACK;
font.fontParameters.borderWidth = 3;
font.fontParameters.flip = true;
font.fontParameters.characters = FreeTypeFontGenerator.DEFAULT_CHARS;
font.fontParameters.size = 96;

manager.load("arial-96.otf", BitmapFont.class, font);

我看不出我做错了什么。

【问题讨论】：

标签： java libgdx truetype

【解决方案1】：

我尝试过这种方式，对我来说效果很好：

public class TestGame extends Game {

    private AssetManager assetManager;
    private SpriteBatch spriteBatch;

    @Override
    public void create() {

        assetManager=new AssetManager();
        spriteBatch=new SpriteBatch();
        FileHandleResolver resolver = new InternalFileHandleResolver();
        assetManager.setLoader(FreeTypeFontGenerator.class, new FreeTypeFontGeneratorLoader(resolver));
        assetManager.setLoader(BitmapFont.class, ".otf", new FreetypeFontLoader(resolver));
        FreetypeFontLoader.FreeTypeFontLoaderParameter size03Params = new FreetypeFontLoader.FreeTypeFontLoaderParameter();
        size03Params.fontFileName = "CHARLEMAGNESTD-BOLD.otf";
        size03Params.fontParameters.size = 96;
        assetManager.load("CHARLEMAGNESTD-BOLD.otf", BitmapFont.class, size03Params);

        assetManager.finishLoading();
    }

    @Override
    public void render() {

        spriteBatch.begin();

        if(assetManager.update()){
            BitmapFont font=assetManager.get("CHARLEMAGNESTD-BOLD.otf");
            font.draw(spriteBatch,"HEOOOW",100,100);
        }

        spriteBatch.end();
    }

    @Override
    public void dispose() {
        spriteBatch.dispose();
        assetManager.dispose();
    }
}

【讨论】：