Android模拟器上的ListView中未显示数据

Question

I've managed to get the back end working for an android app, where it parses an RSS Feed. However I'm having real trouble getting it to display on the GUI. I've read many tutorials, and either I'm doing something nobody else is, or as more likely the case, I'm doing something silly, like not calling something somewhere.

The problem is, after some help for the guys who's already responded, I'm getting null pointer exceptions in my code. I've posted teh errors below for you to take a look at. The code hasn't changed vastly from where I've dumped it on codepad.

I'm parsing the XML using SAX if that makes a blind bit of difference.

I've dumped the pertinent files here in plain text, and sorry that they're in one massive bunch....

Code Dump of Stuff

I just can't figure out where i'm going wrong. Many thanks for your time once more.

The errors from catlog are as follows:

CatLogErrors

Answer 1

    public class WelshboyActivity extends   Activity 
    setContentView(R.layout.main);
    in UpdateGui() ,

        if(feeds.size()!=0){

        ListView itemlist = (ListView) findViewById(R.id.list);   
        ArrayAdapter<BlogPost> adapter = new ArrayAdapter<BlogPost>(this, android.R.layout.simple_list_item_1, feeds);
        itemlist.setAdapter(adapter);

    }else{
         Log.d("TAG","feeds is empty ");
}

Answer 2

If you extend ListActivity and want to use your main.xml then you forgot to call:

setContentView(R.layout.main);

in your onCreate() method(before the feeds = getFeed(feedSource); ). Also if you plan to extend ListActivity then in your layout you must have a ListView element with the id:

android:id="@android:id/list"

Then in your updateGui method you don't have to find the list because the ListActivity will automatically find it as long as you have the above ID :

private void UpdateGui() {
        ArrayAdapter<BlogPost> adapter = new ArrayAdapter<BlogPost>(this, android.R.layout.simple_list_item_1, feeds);
        setListAdapter(adapter);
    }