Java 我可以在后台迭代吗？

我有一个正在冻结我的应用程序的解析查询：

ParseQuery<ParseObject> query = new ParseQuery<>("Puzzle");
query.whereEqualTo("puzzle", "somePuzzle");
query.findInBackground(new FindCallback<ParseObject>() {
    public void done(List<ParseObject> objects, ParseException e) {
        if (e == null) {
            ArrayList<Puzzle> listPuzzle = new ArrayList<>();
            for (ParseObject object : objects) listPuzzle.add(new Puzzle(object));

            ListView list = (ListView) findViewById(R.id.list_puzzle);
            if (list != null && listPuzzle.size() != 0) {
                AdapterPuzzle adapterPuzzle = new AdapterPuzzle(listPuzzle, ScreenPuzzle.this);
                list.setAdapter(adapterPuzzle);
            }
        } else e.printStackTrace();
    }
});

有没有办法在后台运行此迭代器或所有这些操作？有没有办法避免这种冻结？

尝试使用类。它有一种完全适合您的任务的doInBackground方法

编辑：

我正在为需要参考的人添加代码解决方案：

public class ScreenPuzzle extends AppCompatActivity {

    private ListView list;
    private TextView textUnresolved;
    private ProgressBar loading;

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

        list = (ListView) findViewById(R.id.list_puzzle);
        textUnresolved = (TextView) findViewById(R.id.text_unresolved);
        loading = (ProgressBar) findViewById(R.id.loading_rank);

        ParseQuery<ParseObject> query = new ParseQuery<>("Puzzle");
        query.whereEqualTo("puzzle", "somePuzzle");
        query.findInBackground(new FindCallback<ParseObject>() {
            public void done(List<ParseObject> objects, ParseException e) {
                if (e == null) new BackgroundOperation(objects).execute();
                else e.printStackTrace();
            }
        });
    }

    private class BackgroundOperation extends AsyncTask<Void, Void, ArrayList<Puzzle>> {

        private List<ParseObject> objects;
        private ArrayList<Puzzle> listPuzzle;

        public BackgroundOperation(List<ParseObject> objects) { this.objects = objects; }

        @Override
        protected ArrayList<Puzzle> doInBackground(Void... voids) {
            listPuzzle = new ArrayList<>();
            for (ParseObject object : objects) listPuzzle.add(new Puzzle(object));

            return listPuzzle;
        }

        @Override
        protected void onPostExecute(ArrayList<Puzzle> listPuzzle) {
            if (list != null && listPuzzle.size() != 0) {
                final AdapterPuzzle adapterPuzzle = new AdapterPuzzle(listPuzzle, ScreenPuzzle.this);
                list.setAdapter(adapterPuzzle);
            } else textUnresolved.setVisibility(View.VISIBLE);

            loading.setVisibility(View.GONE);
        }
    }
}

公共类ScreenPuzzle扩展了AppCompative活动{
私有列表视图列表；
私有文本视图文本未解析；
私家酒吧；
@凌驾
创建时受保护的void（Bundle savedInstanceState）{
super.onCreate（savedInstanceState）；
setContentView（R.layout.screen_拼图）；
list=（ListView）findViewById（R.id.list\u）；
textUnresolved=（TextView）findViewById（R.id.text\u unresolved）；
加载=（ProgressBar）findViewById（R.id.loading\u rank）；
ParseQuery查询=新的ParseQuery（“拼图”）；
查询：whereEqualTo（“拼图”、“某物拼图”）；
findInBackground（新的FindCallback（）{
公共void done（列出对象，parsee异常）{
如果（e==null）新建后台操作（objects）.execute（）；
否则，例如printStackTrace（）；
}
});
}
私有类BackgroundOperation扩展了异步任务{
私有列表对象；
私有数组列表；
公共后台操作（列出对象）{this.objects=objects；}
@凌驾
受保护的ArrayList doInBackground（无效…无效）{
listPuzzle=新的ArrayList（）；
对于（ParseObject对象：对象）listPuzzle.add（新建Puzzle（对象））；
返回列表；
}
@凌驾
受保护的void onPostExecute（ArrayList listPuzzle）{
if（list！=null&&listPuzzle.size（）！=0）{
最终AdapterPuzzle AdapterPuzzle=新AdapterPuzzle（列表拼图，屏幕拼图，this）；
列表.setAdapter（adapterPuzzle）；
}else textUnresolved.setVisibility（View.VISIBLE）；
loading.setVisibility（View.GONE）；
}
}
}

public class ScreenPuzzle extends AppCompatActivity {

    private ListView list;
    private TextView textUnresolved;
    private ProgressBar loading;

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

        list = (ListView) findViewById(R.id.list_puzzle);
        textUnresolved = (TextView) findViewById(R.id.text_unresolved);
        loading = (ProgressBar) findViewById(R.id.loading_rank);

        ParseQuery<ParseObject> query = new ParseQuery<>("Puzzle");
        query.whereEqualTo("puzzle", "somePuzzle");
        query.findInBackground(new FindCallback<ParseObject>() {
            public void done(List<ParseObject> objects, ParseException e) {
                if (e == null) new BackgroundOperation(objects).execute();
                else e.printStackTrace();
            }
        });
    }

    private class BackgroundOperation extends AsyncTask<Void, Void, ArrayList<Puzzle>> {

        private List<ParseObject> objects;
        private ArrayList<Puzzle> listPuzzle;

        public BackgroundOperation(List<ParseObject> objects) { this.objects = objects; }

        @Override
        protected ArrayList<Puzzle> doInBackground(Void... voids) {
            listPuzzle = new ArrayList<>();
            for (ParseObject object : objects) listPuzzle.add(new Puzzle(object));

            return listPuzzle;
        }

        @Override
        protected void onPostExecute(ArrayList<Puzzle> listPuzzle) {
            if (list != null && listPuzzle.size() != 0) {
                final AdapterPuzzle adapterPuzzle = new AdapterPuzzle(listPuzzle, ScreenPuzzle.this);
                list.setAdapter(adapterPuzzle);
            } else textUnresolved.setVisibility(View.VISIBLE);

            loading.setVisibility(View.GONE);
        }
    }
}