android - 无法恢复 libGDX 中的 Activity

Question

我正在尝试开发一个应用程序。它有一些 Activity ，这些是， SplashActivity， MainMenuActivity，以及 游戏 Activity 。

现在，所有三个 Activity 都扩展了 BaseActivity，后者也扩展了 libgdx 的 AndroidApplication。

在 SplashActivity 和 MainMenuActivity 中，我使用 onCreate、setContentView 布局等编写了纯 Android 特定代码。我没有在这些 Activity 上编写任何 libgdx 代码。

Activity 转换是这样的， SplashActivity(已完成)-> MainMenuActivity(未完成)-> GameActivity

在 GameActivity 上，我设置 ContentView mygame 布局，并编写以下代码:

public void onCreate(Bundle savedInstanceState) {
      super.onCreate(savedInstanceState);
      setContentView(R.layout.mygame);

      gbbrdlyot1 = (RelativeLayout) findViewById(R.id.gbbrdlyot1);
      gameBoard = new RelativeLayout(this);
      RelativeLayout.LayoutParams layoutParams = new RelativeLayout.LayoutParams(newBlockWidth, newBlockWidth);
      gameBoard.setLayoutParams(layoutParams);

      View gameView = initializeForView(new GameView(), true);
      gameBoard.addView(gameView);   

        gbbrdlyot1.addView(gameBoard);
}

但是我在 SplashActivity 上遇到 RuntimeException，我不知道为什么，

    05-27 12:56:22.609:  java.lang.RuntimeException: Unable to resume activity com.game.MyGame/com.game.MyGame.SplashActivity}: java.lang.NullPointerException
05-27 12:56:22.609:  at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2124)
05-27 12:56:22.609:  at android.app.ActivityThread.handleResumeActivity(ActivityThread.java:2139)
05-27 12:56:22.609: at android.app.ActivityThread.handleLaunchActivity(ActivityThread.java:1672)
05-27 12:56:22.609:    at android.app.ActivityThread.access$1500(ActivityThread.java:117)
05-27 12:56:22.609:    at android.app.ActivityThread$H.handleMessage(ActivityThread.java:935)
05-27 12:56:22.609: at android.os.Handler.dispatchMessage(Handler.java:99)
05-27 12:56:22.609: at android.os.Looper.loop(Looper.java:130)
05-27 12:56:22.609: at android.app.ActivityThread.main(ActivityThread.java:3687)
05-27 12:56:22.609: at java.lang.reflect.Method.invokeNative(Native Method)
05-27 12:56:22.609: at java.lang.reflect.Method.invoke(Method.java:507)
05-27 12:56:22.609: at com.android.internal.os.ZygoteInit$MethodAndArgsCaller.run(ZygoteInit.java:867)
05-27 12:56:22.609: at com.android.internal.os.ZygoteInit.main(ZygoteInit.java:625)
05-27 12:56:22.609: at dalvik.system.NativeStart.main(Native Method)
05-27 12:56:22.609: Caused by: java.lang.NullPointerException
05-27 12:56:22.609: at com.badlogic.gdx.backends.android.AndroidApplication.onResume(AndroidApplication.java:249)
05-27 12:56:22.609: at com.game.MyGame.SplashActivity.onResume(SplashActivity.java:43)
05-27 12:56:22.609: at android.app.Instrumentation.callActivityOnResume(Instrumentation.java:1150)
05-27 12:56:22.609: at android.app.Activity.performResume(Activity.java:3832)
05-27 12:56:22.609: at android.app.ActivityThread.performResumeActivity(ActivityThread.java:2114)
05-27 12:56:22.609: ... 12 more

Answer 1

这部分堆栈跟踪:

05-27 12:56:22.609: Caused by: java.lang.NullPointerException
05-27 12:56:22.609: at com.badlogic.gdx.backends.android.AndroidApplication.onResume(AndroidApplication.java:249)
05-27 12:56:22.609: at com.game.MyGame.SplashActivity.onResume(SplashActivity.java:43)

意味着您的 SplashActivity 扩展了 Libgdx AndroidApplication。但你写道:

In SplashActivity, MainMenuActivity, I have written pure android specific code using onCreate, setcontentView a layout and etc. I have not write any libgdx code on that activities.

但是，如果您扩展 AndroidApplication，您将获得一堆在暂停和恢复时间运行的 Libgdx 代码。但您还没有初始化 Libgdx(因为这似乎是您的 GameActivity 创建的副作用。

保持纯 Android Activity 的纯净，并且不要扩展 Libgdx 类。