AndEngine 字体加载：NullPointerException

Question

好的，我一直在学习本教程并实现我的游戏。但是，我在字体对象上得到了一个空指针异常。我已经在 assets/font 文件夹中加载了 font.ttf 文件，这是代码。请帮忙。谢谢...

在我的 gameScene 类中：

      private void createHUD()
 {
      gameHUD = new HUD();
      scoreText = new Text(20, 420, resourcesManager.font, "Score: 0123456789", new TextOptions(HorizontalAlign.LEFT), vbom);
      scoreText = new Text(20, 420,mFont, "Score: 0123456789", new TextOptions(HorizontalAlign.LEFT), vbom);
      scoreText.setSkewCenter(0, 0);    
      scoreText.setText("Score: 0");
      gameHUD.attachChild(scoreText);
      camera.setHUD(gameHUD);
}

在我的 ResourcesManager 类中：

     private void loadMenuFonts()
    {
     FontFactory.setAssetBasePath("font/");
         final ITexture mainFontTexture = new BitmapTextureAtlas(activity.getTextureManager(), 256, 256, TextureOptions.BILINEAR);

     font = FontFactory.createStrokeFromAsset(activity.getFontManager(), mainFontTexture, activity.getAssets(), "font.ttf", 50, true, Color.WHITE, 2, Color.BLACK);
     font.load();
     }

还有日志猫：

     05-12 15:57:37.478: E/AndroidRuntime(20431): java.lang.NullPointerException:    Attempt to invoke interface method 'org.andengine.opengl.font.Letter   org.andengine.opengl.font.IFont.getLetter(char)' on a null object reference
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.opengl.font.FontUtils.measureText(FontUtils.java:95)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.opengl.font.FontUtils.measureText(FontUtils.java:70)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.opengl.font.FontUtils.measureText(FontUtils.java:49)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.setText(Text.java:201)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.<init>(Text.java:159)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.<init>(Text.java:146)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.<init>(Text.java:138)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.<init>(Text.java:110)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.entity.text.Text.<init>(Text.java:102)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at com.packagename.scene.GameScene.createHUD(GameScene.java:55)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at com.packagename.scene.GameScene.createScene(GameScene.java:39)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at com.packagename.base.BaseScene.<init>(BaseScene.java:36)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at com.packagename.scene.GameScene.<init>(GameScene.java:26)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at com.packagename.manager.SceneManager$1.onTimePassed(SceneManager.java:112)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.engine.handler.timer.TimerHandler.onUpdate(TimerHandler.java:98)
     05-12 15:57:37.478: E/AndroidRuntime(20431):   at org.andengine.engine.handler.UpdateHandlerList.onUpdate(UpdateHandlerList.java:47)

Answer 1

试试

BitmapTextureAtlas=new BitmapTextureAtlas(256, 256, TextureOptions.BILINEAR_PREMULTIPLYALPHA);

代替

final ITexture mainFontTexture = new BitmapTextureAtlas(activity.getTextureManager(), 256, 256, TextureOptions.BILINEAR);

Answer 2

好的，终于报错了！错误是在 GameScene 类中创建文本时，必须从 ResourceManager 类访问字体。但是字体没有被加载，因为函数 loadMenuFonts() 没有被调用。因此，将代码 sn-p 移至 loadGameFonts() 函数可确保在调用函数 loadGameResources() 函数时调用 loadGameFonts() 函数..

     public void loadGameResources()
{
    loadGameGraphics();
    loadGameFonts();
    loadGameAudio();
}

还有 loadGameFonts() 函数：

     private void loadGameFonts()
{
    FontFactory.setAssetBasePath("font/");
    final ITexture mainFontTexture = new   BitmapTextureAtlas(activity.getTextureManager(), 256, 256, TextureOptions.BILINEAR);
    font = FontFactory.createStrokeFromAsset(activity.getFontManager(), mainFontTexture, activity.getAssets(), "font.ttf", 50, true, Color.WHITE, 2, Color.BLACK);
    //mainFontTexture.load();
    font.load();
}