调用 onCreate() 时，ListView 不显示任何项

Question

ListView在调用onCreate（）时不显示任何项目，但是当我锁定和解锁屏幕并调用onResume（）时，它会显示。

"标题"是一个异步任务

谁能帮我

protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_main);
    final ListView lvView = (ListView) findViewById(R.id.resList);
    adapter = new CustomAdapter(this, listItems);
    lvView.setAdapter(adapter);
    lvView.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
            Intent myIntent = new Intent(view.getContext(), Detailed.class);
            Nachricht temp = (Nachricht) lvView.getItemAtPosition(position);
            String tempTitel = temp.titel;
            String tempBeschreibung = temp.beschreibung;
            String tempLink = temp.link;
            myIntent.putExtra("Titel", tempTitel);
            myIntent.putExtra("Beschreibung", tempBeschreibung);
            myIntent.putExtra("Link", tempLink);
            view.getContext().startActivity(myIntent);
        }
    });
    new Title().execute();
    updateUI();
}
public void updateUI(){
    adapter.notifyDataSetChanged();
}

这是我的自定义适配器

public class CustomAdapter extends ArrayAdapter<Nachricht> {
public CustomAdapter(Context context, ArrayList<Nachricht> users) {
    super(context, 0, users);
}
@Override
public View getView(int position, View convertView, ViewGroup parent) {
    // Get the data item for this position
    Nachricht user = getItem(position);
    // Check if an existing view is being reused, otherwise inflate the view
    if (convertView == null) {
        convertView = LayoutInflater.from(getContext()).inflate(R.layout.lv_item, parent, false);
    }
    // Lookup view for data population
    TextView tvName = (TextView) convertView.findViewById(R.id.lvItem_title);
    TextView tvHome = (TextView) convertView.findViewById(R.id.lvItem_desc);
    TextView links = (TextView) convertView.findViewById(R.id.link);
    ImageView imgV = (ImageView) convertView.findViewById(R.id.lvItem_pic);
    // Populate the data into the template view using the data object
    tvName.setText(user.titel);
    tvHome.setText(user.beschreibung);
    links.setText(user.link);
    imgV.setImageBitmap(user.bmp);
    // Return the completed view to render on screen
    return convertView;
}

}

Answer 1

"标题"是一个异步任务

这意味着在 UI 线程上执行updateUI();时，它很可能仍然繁忙。你必须确保

adapter.notifyDataSetChanged();

不会太早执行，所以把语句放在AsyncTask的onPostExecute()方法里。

Answer 2

updateUI（） 有可能在 new Title（）.execute（） 之前调用返回任何数据？因此更新了没有数据且不显示任何内容的 UI？