Question

我想在动态创建的列表视图中执行异步任务，但它给了我错误

这是我的代码

public class TenderViewActivity extends ListActivity {  

ArrayList<Spanned> tenders;

@SuppressWarnings("unchecked")
@Override
protected void onCreate(Bundle savedInstanceState){
super.onCreate(savedInstanceState);

Downloaditems dw_tender=new Downloaditems();
dw_tender.execute();        
}//onCreate

@SuppressWarnings("unused")
private class Downloaditems extends AsyncTask<ArrayList<Spanned>, ArrayList<Spanned>, ArrayList<Spanned>> {

@Override
protected ArrayList<Spanned> doInBackground(ArrayList<Spanned>... params) {

Intent intent = getIntent();
cat = intent.getStringExtra(BidActivity.EXTRA_MESSAGE4);
tender_name = intent.getStringExtra(BidActivity.EXTRA_MESSAGE3);
title=intent.getStringExtra(BidActivity.EXTRA_MESSAGE5);
setTitle(title);

ArrayList<Spanned> tender_res=tenderlist(cat,tender_name);
return tender_res;  
}

protected void onPostExecute(ArrayList<Spanned> result) {
setListAdapter(new ArrayAdapter<Spanned>this,R.layout.tender_listing,R.id.basic_details,tenders));

tenders=result;
}   
}

这行 setListAdapter（新的ArrayAdapterthis，R.layout.tender_listing，R.id.basic_details，招标））; 在onpostexecute方法中给出了我的错误

构造函数ArrayAdapter（TenderViewActivity.Downloaditems，int，int，ArrayList）未定义

请帮助..

Answer 1

更改

 setListAdapter(new ArrayAdapter<Spanned>(this,R.layout.tender_listing,R.id.basic_details,tenders));

到

setListAdapter(new ArrayAdapter<Spanned>(TenderViewActivity.this,R.layout.tender_listing,R.id.basic_details,result));

在您的情况下，this不会引用活动背景。

而不是tenders使用result作为最后一个参数。还要添加@Override注释

 @Override
 protected void onPostExecute(ArrayList<Spanned> result) {
 super.onPostExecute(result);

Answer 2

at

setListAdapter(new ArrayAdapter<Spanned>this,R.layout.tender_listing,R.id.basic_details,tenders));

而不是使用TenderViewActivity.this

setlistadapter在onpostexecute中不起作用

2 个答案: