java - 初始化 android 传感器管理器时出错

Question

我一直收到这个错误

12-26 13:00:47.564: E/GameScene(21593): Error intializing sensors
12-26 13:00:47.564: E/GameScene(21593): java.lang.NullPointerException
12-26 13:00:47.564: E/GameScene(21593):     at com.magnusworks.justtic_tac_toe.GameScene.create(GameScene.java:45)
12-26 13:00:47.564: E/GameScene(21593):     at com.magnusworks.justtic_tac_toe.SceneManager$1.doInBackground(SceneManager.java:37)
12-26 13:00:47.564: E/GameScene(21593):     at com.magnusworks.justtic_tac_toe.SceneManager$1.doInBackground(SceneManager.java:1)
12-26 13:00:47.564: E/GameScene(21593):     at android.os.AsyncTask$2.call(AsyncTask.java:288)
12-26 13:00:47.564: E/GameScene(21593):     at java.util.concurrent.FutureTask.run(FutureTask.java:237)
12-26 13:00:47.564: E/GameScene(21593):     at android.os.AsyncTask$SerialExecutor$1.run(AsyncTask.java:231)
12-26 13:00:47.564: E/GameScene(21593):     at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
12-26 13:00:47.564: E/GameScene(21593):     at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
12-26 13:00:47.564: E/GameScene(21593):     at java.lang.Thread.run(Thread.java:841)

在这个位置

/*44*/try{
        /*45*/sm = (SensorManager) this.activity.getSystemService(Context.SENSOR_SERVICE); //<--- here          
/*46*/  acceleration = sm.getDefaultSensor(Sensor.TYPE_ACCELEROMETER);
            sm.registerListener(this, acceleration, SensorManager.SENSOR_DELAY_NORMAL);
        }
        catch(Exception f){
            Log.e("GameScene", "Error intializing sensors", f);
        }

我是否错误地初始化了传感器管理器？

Answer 1

this.activity 在您的情况下为 null。

替换为:

if (this.activity != null) {
    sm = (SensorManager) this.activity.getSystemService(Context.SENSOR_SERVICE);
}