元素不会与ListView的自定义适配器一起显示

因此,我想从我的Listview中自定义元素,并制作了一个自定义适配器。

public class elementList extends BaseAdapter {

Context context;
String[] data;
private static LayoutInflater inflater = null;

public elementList(Context context, String[] data) {
    this.context = context;
    this.data = data;
    inflater = (LayoutInflater)context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
}

@Override
public int getCount() {
    return data.length;
}

@Override
public Object getItem(int position) {
    return data[position];
}

@Override
public long getItemId(int position) {
    return position;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {
    View vi = convertView;
    if(vi == null)
        vi = inflater.inflate(R.layout.task, null);
    TextView text = (TextView)vi.findViewById(R.id.title);
    Log.d("TAG", "DA");
    text.setText(data[position]);
    return vi;
}
}

private void showTasks(){
    final ArrayList<String> taskList = new ArrayList<String>();

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

    final List<String> tasks = new ArrayList<String>(taskList);
    final ArrayAdapter<String> arrayAdapter = new ArrayAdapter<String>(this, android.R.layout.simple_list_item_1, tasks);
    final elementList element = new elementList(this, tasks.toArray(new String[0]));
    listView.setAdapter(element);

    FirebaseAuth mAuth = FirebaseAuth.getInstance();
    FirebaseUser user = mAuth.getCurrentUser();
    FirebaseDatabase database = FirebaseDatabase.getInstance();
    DatabaseReference adress = database.getReference("users/" + user.getUid() + "/tasksList");
    adress.addListenerForSingleValueEvent(new ValueEventListener() {
        @Override
        public void onDataChange(DataSnapshot dataSnapshot) {
            try{
                if(dataSnapshot.getValue() != null){
                    Map<String, String> value = (Map<String, String>)dataSnapshot.getValue();
                    for (Map.Entry<String, String> entry : value.entrySet()){
                        tasks.add(entry.getValue());
                        Log.d("VALOARE", entry.getValue());
                        element.notifyDataSetChanged();
                    }
                }
            }
            catch (Exception e){
                e.printStackTrace();
            }
        }

        @Override
        public void onCancelled(DatabaseError databaseError) {

        }
    });

}

我不理解为什么在使用adapter(元素)时它没有显示我的列表,但如果我使用arrayadapter,它工作得很好。