Android加载带有进度对话框的列表视图

Question

这是我的代码加载列表视图项

  @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
    }
}

当我运行代码时，进度对话框已经出现，但是在关闭该对话框后，我发现列表为空，没有添加任何项目，我不知道这是什么问题，为什么对话框加载后列表为空。请需要帮助，谢谢预先。

Answer 1

在listadapter设置onPostExecute是因为您使用AsyncTask获取适配器的数据和完成之前设定ListAdapter的AsyncTask所以尽量完成后的AsyncTask设置ListAdapter
所以添加这些

 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);
    }