Question

我尝试在片段中创建listview并从数据库加载数据。但我不知道这个:(我得到了一些红十字架并且不知道如何解决它。我从扩展活动而不是片段得到了自己的酸性代码:( 谁都可以帮帮我？

这是代码

public class FragmentaReviews extends SherlockFragment {

private SimpleAdapter adpt;


@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {
    View rootView = inflater.inflate(R.layout.row_main, container,
            false);


    adpt  = new SimpleAdapter(new ArrayList<Review>(), this);
    ListView lView = (ListView) rootView.findViewById(R.id.listview);

    lView.setAdapter(adpt);

    // Exec async load task
    (new AsyncListViewLoader()).execute("http://10.0.3.2/text.php");
return rootView;
}


private class AsyncListViewLoader extends AsyncTask<String, Void, List<Review>> {
    private final ProgressDialog dialog = new ProgressDialog(getActivity());

    @Override
    protected void onPostExecute(List<Review> result) {         
        super.onPostExecute(result);
        dialog.dismiss();
        adpt.setItemList(result);
        adpt.notifyDataSetChanged();
    }

    @Override
    protected void onPreExecute() {     
        super.onPreExecute();
        dialog.setMessage("Downloading Reviews...");
        dialog.show();          
    }

    @Override
    protected List<Review> doInBackground(String... params) {
        List<Review> result = new ArrayList<Review>();

        try {
            URL u = new URL(params[0]);

            HttpURLConnection conn = (HttpURLConnection) u.openConnection();
            conn.setRequestMethod("GET");

            conn.connect();
            InputStream is = conn.getInputStream();

            // Read the stream
            byte[] b = new byte[1024];
            ByteArrayOutputStream baos = new ByteArrayOutputStream();

            while ( is.read(b) != -1)
                baos.write(b);

            String JSONResp = new String(baos.toByteArray());

            JSONArray arr = new JSONArray(JSONResp);
            for (int i=0; i < arr.length(); i++) {
                result.add(convertReview(arr.getJSONObject(i)));
            }

            return result;
        }
        catch(Throwable t) {
            t.printStackTrace();
        }
        return null;
    }

    private Review convertReview(JSONObject obj) throws JSONException {
        String id = obj.getString("id");
        String name = obj.getString("name");



        return new Review(id, name);
    }

}

}

红十字会

adpt  = new SimpleAdapter(new ArrayList<Review>(), this);

adpt.setItemList(result);

这里是适配器

public class SimpleAdapter extends ArrayAdapter<Review> {

private List<Review> itemList;
private Context context;

public SimpleAdapter(List<Review> itemList, Context ctx) {
    super(ctx, android.R.layout.simple_list_item_1, itemList);
    this.itemList = itemList;
    this.context = ctx;     
}

public int getCount() {
    if (itemList != null)
        return itemList.size();
    return 0;
}

public Review getItem(int position) {
    if (itemList != null)
        return itemList.get(position);
    return null;
}

public long getItemId(int position) {
    if (itemList != null)
        return itemList.get(position).hashCode();
    return 0;
}

@Override
public View getView(int position, View convertView, ViewGroup parent) {

    View v = convertView;
    if (v == null) {
        LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        v = inflater.inflate(R.layout.fragmenta_review, null);
    }


    Review c = itemList.get(position);

    TextView text = (TextView) v.findViewById(R.id.id);
    text.setText(c.getid());

    TextView text1 = (TextView) v.findViewById(R.id.name);
    text1.setText(c.getname());




    return v;

}

public List<Review> getItemList() {
    return itemList;
}

public void setItemList(List<Review> itemList) {
    this.itemList = itemList;
}

}

Answer 1

好的，SimpleAdapter的构造函数将Context对象作为其第二个参数。您传入的'this'因此不是上下文对象（例如Activity），因此您必须传入上下文对象。 'this'指的是你的FragmentReviews类。您可以使用this.getActivity（）作为构造函数的第二个参数。您可能需要将代码更改为以下内容：

Context ctx = (Context)(this.getActivity());
adpt  = new SimpleAdapter(new List<Review>(), ctx);

您的构造函数使用List对象，但您使用ArrayList对象调用它。

片段中的android listview无法定义适配器

1 个答案: