Android加載帶有進度對話框的列表視圖

Question

這是我的代碼加載列表視圖項

  @SuppressLint("DefaultLocale")
   public class SearchList extends Activity {

  private ArrayList<String> founded = new ArrayList<String>();
  private OrderAdapter m_adapter;


ListView lv;

/** Called when the activity is first created. */
@SuppressLint("DefaultLocale")
@Override
public void onCreate(Bundle savedInstanceState) {
    super.onCreate(savedInstanceState);
    setContentView(R.layout.searchlist);
    lv = (ListView) findViewById(R.id.listView1);

    new Load().execute();

    m_adapter = new OrderAdapter(this, R.layout.itemview, founded);

    lv.setAdapter(m_adapter);
    lv.setTextFilterEnabled(true);
    }

  private class Load extends AsyncTask<Void, Void, Void> {

    ProgressDialog progress;

    @Override
    protected void onPreExecute() {
        progress = new ProgressDialog(SearchList.this);
        progress.setMessage("loading....");
        progress.show();
    }

    @Override
    protected Void doInBackground(Void... params) {
             try {

            for (int i = 0; i <500000; i++) {
             founded.add("String "+i);
               }

        } catch (Exception e) {

        }
            return null;
    }

    @Override
    protected void onPostExecute(Void result) {

        // write display tracks logic here
        progress.dismiss(); // dismiss dialog
    }
}

當我運行代碼時，進度對話框已經出現，但是在關閉該對話框后，我發現列表為空，沒有添加任何項目，我不知道這是什么問題，為什么對話框加載后列表為空。請需要幫助，謝謝預先。

Answer 1

在listadapter設置onPostExecute是因為您使用AsyncTask獲取適配器的數據和完成之前設定ListAdapter的AsyncTask所以盡量完成后的AsyncTask設置ListAdapter
所以添加這些

 m_adapter = new OrderAdapter(this, R.layout.itemview, founded);
lv.setAdapter(m_adapter);
lv.setTextFilterEnabled(true);

在onPostExecute方法而不是onCreate方法中的行

 @Override
    protected void onPostExecute(Void result) {

        // write display tracks logic here
        progress.dismiss(); // dismiss dialog
     m_adapter = new OrderAdapter(YourActivity.this, R.layout.itemview, founded);
     lv.setAdapter(m_adapter);
     lv.setTextFilterEnabled(true);
    }