getView（）。findViewById（）的NullPointerException

Question

im试图用ListView来实现一个Fragment，该片段采用EditText字段的Input，创建一个对象，然后在ListView上表示这些对象。但是，当我尝试使用ArrayAdapter时，出现NullPointerException。我正在使用一个包含3个String参数的名为“ Event”的对象的ArrayList。我也实现了我自己的arrayAdapter，但在相同的Exception情况下也不起作用。

//onCreateView 

    @Override
    public View onCreateView(LayoutInflater inflater,ViewGroup container, Bundle savedInstanceState) {
        if(savedInstanceState != null) {
            mCurrentPosition = savedInstanceState.getInt(ARG_POSITION);
        }


 //       Button addButton = (Button) getActivity().findViewById(R.id.BtnAddRoommate);
//        addButton.setOnClickListener(this);

        generateData();
        //useListAdapter(container, inflater);
        useSimpleAdapter();

        return inflater.inflate(R.layout.fragment_calendar, container, false);
    }

// arrayAdapter的方法

   public void useSimpleAdapter(){
        Log.i(TAG, "Simple Adapter in use");


// m_EventList is the ArrayList<Event> that i use

        simpleAdapter = new ArrayAdapter<Event>(this.getContext(), android.R.layout.simple_list_item_1, m_EventList);
        ListView listView = (ListView) getView().findViewById(R.id.lvEvents);
//lvEvents is the ListView Id from the .xml file.

        // Attach the adapter to a ListView
        listView.setAdapter(simpleAdapter);
    }

XML文件：

<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
    android:layout_width="match_parent" android:layout_height="match_parent">

<!-- editTexts and buttons ommited for readability-->


    <ListView
        android:id="@+id/lvEvents"
        android:layout_width="395dp"
        android:layout_height="352dp"
        android:layout_alignParentLeft="true"
        android:layout_alignParentStart="true"
        android:layout_below="@+id/BtnAddRoommate"
        android:layout_marginTop="31dp" />

</RelativeLayout>