Question

我正在尝试使用远程数据填充列表视图，我将这部分应用程序基于教程代码。在教程中，他们只使用类，但在我的使用中我想使用片段，因为我还在将滑动导航栏集成到应用程序中。这很可能是我的一个愚蠢的错误，但是我可以使用一些方向，谢谢。

这是我得到的错误：

The constructor LazyAdapter(HomeFragment, ArrayList<HashMap<String,String>>) is undefined

这发生在HomeFragment的以下行：

// Getting adapter by passing xml data ArrayList
            adapter=new LazyAdapter(HomeFragment.this, songsList);        
            list.setAdapter(adapter);

HomeFragment代码：

public class HomeFragment extends Fragment {

    // All static variables
        static final String URL = "http://api.androidhive.info/music/music.xml";
        // XML node keys
        static final String KEY_SONG = "song"; // parent node
        static final String KEY_ID = "id";
        static final String KEY_TITLE = "title";
        static final String KEY_ARTIST = "artist";
        static final String KEY_DURATION = "duration";
        static final String KEY_THUMB_URL = "thumb_url";

        ListView list;
        LazyAdapter adapter;

    public HomeFragment(){}

    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {

        View rootView = inflater.inflate(R.layout.blog, container, false);



            ArrayList<HashMap<String, String>> songsList = new ArrayList<HashMap<String, String>>();

            XMLParser parser = new XMLParser();
            String xml = parser.getXmlFromUrl(URL); // getting XML from URL
            Document doc = parser.getDomElement(xml); // getting DOM element

            NodeList nl = doc.getElementsByTagName(KEY_SONG);
            // looping through all song nodes <song>
            for (int i = 0; i < nl.getLength(); i++) {
                // creating new HashMap
                HashMap<String, String> map = new HashMap<String, String>();
                Element e = (Element) nl.item(i);
                // adding each child node to HashMap key => value
                map.put(KEY_ID, parser.getValue(e, KEY_ID));
                map.put(KEY_TITLE, parser.getValue(e, KEY_TITLE));
                map.put(KEY_ARTIST, parser.getValue(e, KEY_ARTIST));
                map.put(KEY_DURATION, parser.getValue(e, KEY_DURATION));
                map.put(KEY_THUMB_URL, parser.getValue(e, KEY_THUMB_URL));

                // adding HashList to ArrayList
                songsList.add(map);
            }


            list=(ListView)getView().findViewById(R.id.list);

            // Getting adapter by passing xml data ArrayList
            adapter=new LazyAdapter(HomeFragment.this, songsList);        
            list.setAdapter(adapter);


            // Click event for single list row
            list.setOnItemClickListener(new OnItemClickListener() {

                @Override
                public void onItemClick(AdapterView<?> parent, View view,
                        int position, long id) {


                }
            });     
        }   
    }

ListAdapters代码：

public class LazyAdapter extends BaseAdapter {

    private Activity activity;
    private ArrayList<HashMap<String, String>> data;
    private static LayoutInflater inflater=null;
    public ImageLoader imageLoader; 

    public LazyAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
        activity = a;
        data=d;
        inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader=new ImageLoader(activity.getApplicationContext());
    }

    public int getCount() {
        return data.size();
    }

    public Object getItem(int position) {
        return position;
    }

    public long getItemId(int position) {
        return position;
    }

    public View getView(int position, View convertView, ViewGroup parent) {
        View vi=convertView;
        if(convertView==null)
            vi = inflater.inflate(R.layout.list_row, null);

        TextView title = (TextView)vi.findViewById(R.id.title); // title
        TextView artist = (TextView)vi.findViewById(R.id.artist); // artist name
        TextView duration = (TextView)vi.findViewById(R.id.duration); // duration
        ImageView thumb_image=(ImageView)vi.findViewById(R.id.list_image); // thumb image

        HashMap<String, String> song = new HashMap<String, String>();
        song = data.get(position);

        // Setting all values in listview
        title.setText(song.get(HomeFragment.KEY_TITLE));
        artist.setText(song.get(HomeFragment.KEY_ARTIST));
        duration.setText(song.get(HomeFragment.KEY_DURATION));
        imageLoader.DisplayImage(song.get(HomeFragment.KEY_THUMB_URL), thumb_image);
        return vi;
    }
}

Answer 1

更改

adapter=new LazyAdapter(HomeFragment.this, songsList);

到

adapter=new LazyAdapter(getActivity(), songsList);

public final Activity getActivity ()

返回此片段当前与之关联的活动。

同时更改

list=(ListView)getView().findViewById(R.id.list);

到

list=(ListView)rootView.findViewById(R.id.list);

还要确保您在bakgroud线程上进行与网络相关的操作。

String xml = parser.getXmlFromUrl(URL);

编辑：onCreateView

中缺少返回语句

       });    
    return rootView;
  }

构造函数Adapter（HomeFragment，ArrayList <hashmap <string，string>＆gt;）未定义</hashmap <string，string>

1 个答案: