我有一個NullPointerException當我嘗試設置ProgessBar在onPreExecute AsyncTask (mProgressBar.setVisibility(View.VISIBLE);)
中可見。我不知道哪裏出了問題!謝謝大家!NullpointerException在進度條的AsyncTask的onPreExcute
<ProgressBar
android:id="@+id/pb_featured_game_progress"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:visibility="gone"
/>
public class MainActivity extends Activity {
...
private ProgressBar mProgressBar;
@Override
protected void onCreate(Bundle savedInstanceState) {
new FetchGamesTask().execute();
private class FetchGamesTask extends
AsyncTask<Integer, Integer, List<GameInfo>> {
@Override
protected void onPreExecute() {
// TODO Auto-generated method stub
super.onPreExecute();
mProgressBar = (ProgressBar)findViewById(R.id.pb_featured_game_progress);
mProgressBar.setVisibility(View.VISIBLE);
}
首先它似乎你在活動 – donfuxx