libgdx AndroidApplication類

Question

AndroidApplication類擴展機器人活動類，那麼，爲什麼它給出以下錯誤：

06-06 05:47:17.610: E/AndroidRuntime(12567): java.lang.RuntimeException: Unable to resume activity {com.badlogic.drop/com.badlogic.drop.MainActivity}: java.lang.NullPointerException 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2288) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2316) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1836) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.access$500(ActivityThread.java:122) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread$H.handleMessage(ActivityThread.java:1024) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.os.Handler.dispatchMessage(Handler.java:99) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.os.Looper.loop(Looper.java:132) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.main(ActivityThread.java:4123) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at java.lang.reflect.Method.invokeNative(Native Method) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at java.lang.reflect.Method.invoke(Method.java:491) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:841) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:599) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at dalvik.system.NativeStart.main(Native Method) 
06-06 05:47:17.610: E/AndroidRuntime(12567): Caused by: java.lang.NullPointerException 
06-06 05:47:17.610: E/AndroidRuntime(12567): at com.badlogic.gdx.backends.android.AndroidApplication.onResume(AndroidApplication.java:223) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1153) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.Activity.performResume(Activity.java:4468) 
06-06 05:47:17.610: E/AndroidRuntime(12567): at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2278) 

我從活動擴展MainActivity類別到AndroidApplication，然後它給上述錯誤。但是，如果我取消評論部分的註釋，那麼它就可以完美工作。請幫助解決它。

public class MainActivity extends AndroidApplication { 


AndroidApplication app; 
LinearLayout m3d; 

    @Override 
    public void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.main); 

/* AndroidApplicationConfiguration config = new AndroidApplicationConfiguration(); 
     config.useGL20 = false; 
     config.useAccelerometer = false; 
     config.useCompass = false; 

     m3d = (LinearLayout) findViewById(R.id.m3d); 
     View m3dDrop = initializeForView(new Drop(), config); 

     m3d.addView(m3dDrop); */ 

    } 


} 

Answer 1

我想這是因爲你沒有打電話initializeForView()，這就需要在onCreate()被調用。 documentation解釋說你需要所有的評論代碼。

要解決問題，只需將註釋代碼重新放入即可。爲什麼您甚至要將其取出？