Android AsyncTask完成执行后未更新ExpandableListView
我有一个ExpandableListView,它是作为活动的一部分创建的:Android AsyncTask完成执行后未更新ExpandableListView,android,android-asynctask,expandablelistview,Android,Android Asynctask,Expandablelistview,我有一个ExpandableListView,它是作为活动的一部分创建的: @Override public void onCreate(Bundle savedInstanceState) { super.onCreate(savedInstanceState); setContentView(R.layout.news); // create the exandable list view widget newsListAdapter = new
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.news);
// create the exandable list view widget
newsListAdapter = new NewsListAdapter(this.getApplicationContext());
newsListView = (ExpandableListView) findViewById(R.id.news_list_view);
newsListView.setAdapter(newsListAdapter);
final Button homeButton = (Button) findViewById(R.id.home_btn);
// go back to the home page
homeButton.setOnClickListener(new View.OnClickListener() {
public void onClick(View view) {
startActivity(new Intent(view.getContext(), HomeActivity.class));
}
});
newsListView.setOnGroupClickListener(new OnGroupClickListener() {
public boolean onGroupClick(ExpandableListView parent, View view, int groupPosition, long arg3) {
return false;
}
});
newsListView.setOnChildClickListener(new OnChildClickListener() {
public boolean onChildClick(ExpandableListView parent, View view,
int groupPosition, int childPosition, long id) {
return false;
}
});
showLoadingProgressDialog();
downloadRssFeedTask = new DownloadRssFeedTask();
downloadRssFeedTask.execute();
}
正如您从代码中看到的,它在异步任务中启动并从RSS提要中执行拉取操作
AsyncTask完成后,“进度”对话框被取消,活动被告知任务已完成:
private void responseReceived(Channel newsResponse) {
if (newsResponse != null)
newsListAdapter.buildView(newsResponse);
}
else {
Toast toast = Toast.makeText(this.getApplicationContext(),
"There is no news available at this time.",
Toast.LENGTH_LONG);
toast.show();
}
}
但是,ExpandableListView在加载数据后不会重新绘制/刷新自身,它是一个空白屏幕。如何让ExpandableListView使用RSS数据刷新自身?我尝试了invalidate
和refreshDrawableState
但没有任何乐趣
想法?我猜您在下载RSS提要后忘记调用适配器上的
notifyDataSetChanged()
方法(可能您应该在AsyncTask
中的onPostExecute()
方法中调用它)。这应该有效
newsListAdapter.notifyDataSetChanged()
啊!神奇的答案是适配器类上的notifyDataSetChanged()
。