Question

我正在为进程创建进度对话框。但我在我的线程中采用空指针异常。但是，当我删除进度对话框。我不再例外了。

我的代码就是这个

public class PlayedActivity extends ListActivity {

private PullToRefreshListView listView;

final Context context = this;

public Handler handler;

Runnable sendNumbers2;

List<On> playedOn;

DatabaseHandlerOn db;

private ProgressDialog m_ProgressDialog;

private ArrayList<On> m_results = null;
private PlayedOnAdapter m_adapter;



    @SuppressLint({ "HandlerLeak", "HandlerLeak" })
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.activity_playedonnumara);


            db = new DatabaseHandlerOnNumara(getApplicationContext());

            m_results = new ArrayList<OnNumara>();

        this.m_adapter = new PlayedOnNumaraAdapter(this, R.layout.playedrowon, m_results);
        this.setListAdapter(this.m_adapter);

        sendNumbers2 = new Runnable() {

            @Override
            public void run() {

                playedOn = db.getAllContacts();      

                for (On on : playedOn) {

                    m_results.add(on);  

                }  


                Collections.reverse(m_results);

                //m_ProgressDialog.dismiss();

                handler.sendEmptyMessage(0);
            }
        };
            Thread thread = new Thread(sendNumbers2,"sendNumbers2");
            thread.start();

            /*m_ProgressDialog = ProgressDialog.show(PlayedOnNumaraActivity.this,
                    "",getString(R.string.PleaseWait), true);

            m_ProgressDialog.setCancelable(true);
        */

            handler = new Handler() {
                @Override
                public void handleMessage(Message msg) {


                    m_adapter.notifyDataSetChanged();


                }

             };

        }
}

}

上面的代码正在运行，并且在评论进度对话框代码时不会例外

Answer 1

如果没有LogCat日志，我只能猜测。

启动线程后定义

m_ProgressDialog。为什么？在线程启动之前定义它。

此外，我建议使用AsyncTask来代替。有关详细信息，请参阅Painless Threading。

当我删除进度对话框时，它可以工作。为什么？

1 个答案: