Java Android getContentResolver NullPointerException

我是Android新手。当调用getContentResolver函数时，我总是得到NullPointerException。我不知道为什么。代码如下：

@EActivity(R.layout.activity_job_details)
@OptionsMenu(R.menu.main)
public class JobDetailsActivity extends ActionBarActivity {
    @Extra
    Job jobObject;

    @ViewById
    ListView lwPickups;

    PickupAdapter adapter;

    @AfterViews
    public void afterViews() {
            initActionBar();

            adapter = new PickupAdapter(JobDetailsActivity.this,
                            R.layout.row_pickup, R.id.twPickup, jobObject.getPickups());
            lwPickups.setAdapter(adapter);
    }


    private void initActionBar() {
            ActionBar actionBar = getSupportActionBar();
            actionBar.setTitle(jobObject.getDesc());
            actionBar.setDisplayHomeAsUpEnabled(true);
            actionBar.setHomeButtonEnabled(true);

    }

然后我尝试在同一个类中运行查询事件：

    boolean result=queryEvent("123",JobDetailsActivity.this);
    @SuppressLint("NewApi")
    public boolean queryEvent(String event_id,Context context) {
            String[] projection= new String[]{Events.TITLE};
            ContentResolver contentResolver=context.getContentResolver(); // NullPointerException
            Cursor calCursor=contentResolver.query(Events.CONTENT_URI, projection, Events._ID+"="+event_id, null, null);
            if(calCursor.moveToFirst()){
                    do{
                            String id = calCursor.getString(0);
                            if(id==event_id){
                                    return true;
                            }
                    }while(calCursor.moveToNext());
            }
            return false;
    }

}

---

有人能帮忙吗？这是否导致在创建活动之前无法访问getContentResolver？如果是，在本例中，当我使用@EActivityR.layout.activity\u job\u details时，我应该将getContentResolver放在哪里？谢谢

调用活动上下文时可能出错，请尝试使用this.getApplicationContext代替JobDetailsActivity.this like boolean result=queryEvent123，this.getApplicationContext；更改到此.getApplicationContext后仍然不起作用。我已粘贴了logCat:05-06 22:50:33.058:E/AndroidRuntime5267:原因：java.lang.NullPointerException 05-06 22:50:33.058:E/AndroidRuntime5267:在android.content.ContextWrapper.GetApplicationContextWrapper.java:109这一次NullPointerException发生在getApplicationContext