android SimpleCrsorAdapter在异步任务中捕获错误
我不知道在AsyncTask中添加SimpleCorsOrAdapter时为什么会遇到错误android SimpleCrsorAdapter在异步任务中捕获错误,android,android-asynctask,simplecursoradapter,Android,Android Asynctask,Simplecursoradapter,我不知道在AsyncTask中添加SimpleCorsOrAdapter时为什么会遇到错误 private class LoadNewsLists extends AsyncTask<String, Void, Cursor> { @Override protected void onPreExecute() { } @Override protected Cursor doInBackground(final
private class LoadNewsLists extends AsyncTask<String, Void, Cursor> {
@Override
protected void onPreExecute() {
}
@Override
protected Cursor doInBackground(final String... args) {
Cursor cursor = dbHelper.fetchMainActivity();
return cursor;
}
protected void onPostExecute(final Cursor cursor) {
String[] columns = new String[] {
DatabaseUtil.rtitle,
DatabaseUtil.rtypeof
};
// the XML defined views which the data will be bound to
int[] to = new int[] {
R.id.idTitle,
R.id.idType
};
// create the adapter using the cursor pointing to the desired data
//as well as the layout information
dataAdapter = new SimpleCursorAdapter(
MainActivity.this, R.layout.listhome,
cursor,
columns,
to,
0);
listView = (ListView) findViewById(R.id.list);
listView.setAdapter(dataAdapter);
}
检查dbHelper实例。它可能为空,这意味着此行将通过NPE:
Cursor cursor = dbHelper.fetchMainActivity();
真是糟糕。。。!谢谢我忘了初始化dbHelper。
Cursor cursor = dbHelper.fetchMainActivity();