Android 如何在我的自定义 Listview 中实现 AsyncTask

Question

当我运行我的代码时，我总是得到一个关于 Skipped 303 frames 的日志!应用程序可能在其主线程上做了太多工作。 如何在下面的代码中实现 AsyncTask，以及如何在从我的 Parse.com 数据库之一获取数据时显示进度条。如果有任何帮助，我将不胜感激。

---

这是我的 Activity 代码:

@Override
protected void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.activity_doctors_name_list);

    Bundle extras = getIntent().getExtras();
    final String key = extras.getString("KEY");
    ListView lvDoctorsName = (ListView) findViewById(R.id.lvDoctorsName);

    ParseQueryAdapter.QueryFactory<ParseObject> factory = new ParseQueryAdapter.QueryFactory<ParseObject>() {
        public ParseQuery create() {
            ParseQuery query = new ParseQuery("doctors");
            query.whereContains("name", key);
            return query;
        }
    };
    CustomLayout urgentAdapter = new CustomLayout(this, factory);
    lvDoctorsName.setAdapter(urgentAdapter);

    TextView empty = (TextView) findViewById(R.id.empty_list_item);
    lvDoctorsName.setEmptyView(empty);

    itemClickListener();
}

public void itemClickListener() {
    ListView lvDoctorsName = (ListView) findViewById(R.id.lvDoctorsName);
    lvDoctorsName.setOnItemClickListener(new AdapterView.OnItemClickListener() {
        @Override
        public void onItemClick(AdapterView<?> parent, View view, int position, long id) {

            ParseObject item = (ParseObject) parent.getAdapter().getItem(position);
            String objectID = item.getObjectId().toString();
            Intent i = new Intent();
            i.setClass(getApplicationContext(), DoctorPage.class);
            //i.putExtra("new_variable_name",value);
            i.putExtra("objectID", objectID);
            startActivity(i);
        }
    });

}

这里是我的自定义布局:

public class CustomLayout extends ParseQueryAdapter<ParseObject> {


public CustomLayout(Context context, QueryFactory<ParseObject> queryFactory) {
    super(context, queryFactory);
}


@Override
public View getItemView(ParseObject object, View v, ViewGroup parent) {
    if (v == null) {
        v = View.inflate(getContext(), R.layout.row, null);
    }
    super.getItemView(object, v, parent);

    TextView titleTextView = (TextView) v.findViewById(R.id.text1);
    titleTextView.setText(object.getString("name"));

    TextView titleTextView2 = (TextView) v.findViewById(R.id.text2);
    titleTextView2.setText(object.getString("city"));

    return v;
}

Answer 1

我看到的一个问题是，每次调用 getItemView() 时，您都在调用 findViewById()； findViewById() 是一项开销很大的操作。你应该实现类似 ViewHolder 的东西模式来避免这种情况。