java ArrayAdapter片段中的空指针

Question

首先，我在论坛上看到了很多类似的问题，但没有一个能回答这个问题。我什么都试过了。请帮忙

我有一个arrayList，它在片段中从firebase数据库加载数据，但在这一行listView.setAdapter(arrayAdapter);上总是有一个空指针

 @Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
                         Bundle savedInstanceState) {

    View v = inflater.inflate(R.layout.fragment_my_account, container, false);

    //chat rooms code///

    listView = (ListView) v.findViewById(R.id.chatRoomsList);

/////added this check////
    if(listView == null){
     Log.d("mytag1","The listview is null");
    }if(listView != null){
     Log.d("mytag2","The listview is not null");
            }

    arrayAdapter = (new ArrayAdapter<String>(getActivity(),
            安卓.R.layout.simple_list_item_1 , list_of_rooms));

    listView.setAdapter(arrayAdapter);

    add_room.setOnClickListener(new View.OnClickListener() {
        @Override
        public void onClick(View view) {

            Map<String,Object> map = new HashMap<String, Object>();
            map.put(room_name.getText().toString(),"");
            DBRChatrooms.updateChildren(map);

        }
    });

    DBRChatrooms.addValueEventListener(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {

            Set<String> set = new HashSet<String>();
            Iterator i = dataSnapshot.getChildren().iterator();

            while (i.hasNext()){
                set.add(((DataSnapshot)i.next()).getKey());
            }

            list_of_rooms.clear();
            list_of_rooms.addAll(set);

            arrayAdapter.notifyDataSetChanged();
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

    listView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> adapterView, View view, int i, long l) {

            Intent intent = new Intent(getActivity().getApplicationContext(),ChatRoom.class);
            intent.putExtra("room_name",((TextView)view).getText().toString() );
            intent.putExtra("user_name",name);
            startActivity(intent);
        }
    });


    ////////////////end of chat room code//////////////


    //return view at the end
    return v;
}

其余的：

private ListView listView;
private ArrayAdapter<String> arrayAdapter;
private ArrayList<String> list_of_rooms = new ArrayList<>();
private DatabaseReference DBRChatrooms = FirebaseDatabase.getInstance().getReference("Chatrooms");

阅读后，我了解到arrayAdapter中的getActivity()存在问题。但我什么都试过了

1. getContext()
2. getContext().getApplicationContext()
3. getActivity().getApplicationContext()
4. v.getContext/v.getActivity
5. and so on, ive tried like 10 different things, always null

我甚至试着把代码放到创建的活动中，再次尝试了所有仍然不起作用的东西

Answer 1

我用错误的布局给充气机充气。。。。不管怎样，谢谢你的帮助，我在这过程中确实学到了一些东西