java - 我无法在 Android Fragment 中使用 textview 填充 gridview

Question

我无法使用 fragment 填充 gridview 内的 imageview TextView 。

它显示空白而不是我的项目中填充的 gridview 可以请任何人看到下面的代码并让我知道我必须更改什么

图像和文本的填充是动态地从 mysql 数据库

public class StoreHomeFragment extends Fragment {
final ArrayList<HashMap<String, String>> MyArrList = new ArrayList<HashMap<String, String>>();
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
        Bundle savedInstanceState) {

    View rootView = inflater.inflate(R.layout.store_home, container, false);
    final GridView gridView1 = (GridView)rootView.findViewById(R.id.store_home_gridview); 
    gridView1.setAdapter(new ImageAdapter(rootView.getContext(), MyArrList));
    return rootView;
}

//Activity 已创建

@Override

 public void onActivityCreated(Bundle savedInstanceState) {
     super.onActivityCreated(savedInstanceState);

     String url = "http://192.168.1.132/Android/App/good.php"; //url where i am using select query and retrieving it from database

        try {
            JSONArray data = new JSONArray(getJSONUrl(url));

            HashMap<String, String> map;

            for(int i = 0; i < data.length(); i++){
                JSONObject c = data.getJSONObject(i);//retrieving from db
                map = new HashMap<String, String>();
                map.put("name", c.getString("name"));
                map.put("artist", c.getString("artist"));
                map.put("price", c.getString("price"));
                map.put("image", c.getString("image"));


                MyArrList.add(map);
            }           

            //gridView1.setAdapter(new ImageAdapter(this,MyArrList));

        } catch (JSONException e) {

            e.printStackTrace();
        } catch (Exception e) {

            e.printStackTrace();
        }

    }      

//我已经使用了imageAdapter

class ImageAdapter extends BaseAdapter 

{
    private Context context;
    public ImageView imageView;
    private ArrayList<HashMap<String, String>> MyArr = new ArrayList<HashMap<String, String>>();

    public ImageAdapter(Context c,ArrayList<HashMap<String, String>> list) 
    {   
        context = c;

        MyArr = list;
    }

    public int getCount() {

        return MyArr.size();
    }

    public Object getItem(int position) {

        return position;
    }

    public long getItemId(int position) {

        return position;
    }
    public View getView(int position, View convertView, ViewGroup parent) {

        LayoutInflater inflater = (LayoutInflater) context
                .getSystemService(Context.LAYOUT_INFLATER_SERVICE);

        if (convertView == null) {
            convertView = inflater.inflate(R.layout.store_home_gridview_row, null); 
        }

        TextView tv_title = (TextView) convertView.findViewById(R.id.textview_name);
        tv_title.setText("Title:"+MyArr.get(position).get("name"));

        TextView tv_artist = (TextView) convertView.findViewById(R.id.textview_artist);
        tv_artist.setText("Artist:"+MyArr.get(position).get("artist"));

        TextView tv_duration = (TextView) convertView.findViewById(R.id.textview_price);
        tv_duration.setText("Price:"+MyArr.get(position).get("price"));

        String abc = (MyArr.get(position).get("image"));
        String abcd = "http://192.168.1.132/images/products/"+abc;

        imageView = (ImageView) convertView.findViewById(R.id.imageView1);
        try
        {
            URL url3 = null;
            try {
                url3 = new URL(abcd);
                } catch (Exception e) {

                e.printStackTrace();
            }
            Bitmap bmp = BitmapFactory.decodeStream(url3.openConnection().getInputStream()); //image is populated 
            imageView.setImageBitmap(bmp);
        }
        catch(Exception par)
        {
            imageView.setImageResource(android.R.drawable.ic_menu_report_image);
        }
        return convertView;         
    }

} 



    /*** Get JSON Code from URL ***/
    public String getJSONUrl(String url) {
        StringBuilder str = new StringBuilder();
        HttpClient client = new DefaultHttpClient();
        HttpGet httpGet = new HttpGet(url);
        try 
        {
            HttpResponse response = client.execute(httpGet);
            StatusLine statusLine = response.getStatusLine();
            int statusCode = statusLine.getStatusCode();
            System.out.println ( "status Code : " + statusCode );
            if (statusCode == 200) 
            { 
                HttpEntity entity = response.getEntity();
                InputStream content = entity.getContent();
                BufferedReader reader = new BufferedReader(new InputStreamReader(content));
                String line;
                while ((line = reader.readLine()) != null) 
                {
                    str.append(line);
                }
            }   
            else 
            {
                Log.e("Log", "Failed to download file..");
            }
        } 
        catch (ClientProtocolException e) 
        {
            e.printStackTrace();
        } 
        catch (IOException e) 
        {
            e.printStackTrace();
        }
        System.out.println ( "str : " + str.toString() );
        return str.toString();
    }


 }

Answer 1

按照步骤操作希望这对您有帮助

1) 从 onCreateView() 方法中删除这些行

final GridView gridView1 = (GridView)rootView.findViewById(R.id.store_home_gridview); 
    gridView1.setAdapter(new ImageAdapter(rootView.getContext(), MyArrList));

2)修改onActivityCreated()如下

@Override
public void onActivityCreated(Bundle savedInstanceState) {
    super.onActivityCreated(savedInstanceState);
    new AsyncTask<Void, Void, Void>() {

        @Override
        protected Void doInBackground(Void... params) {
            String url = "http://192.168.1.132/Android/App/good.php";

            try {
                JSONArray data = new JSONArray(getJSONUrl(url));

                HashMap<String, String> map;

                for (int i = 0; i < data.length(); i++) {
                    JSONObject c = data.getJSONObject(i);

                    map = new HashMap<String, String>();
                    map.put("name", c.getString("name"));
                    map.put("artist", c.getString("artist"));
                    map.put("price", c.getString("price"));
                    map.put("image", c.getString("image"));

                    MyArrList.add(map);
                }

            } catch (JSONException e) {

                e.printStackTrace();
            } catch (Exception e) {

                e.printStackTrace();
            }
            return null;
        }

        @Override
        protected void onPostExecute(Void result) {
            super.onPostExecute(result);
            final GridView gridView1 = (GridView) rootView.findViewById(R.id.store_home_gridview);
            gridView1.setAdapter(new ImageAdapter(getActivity(), MyArrList));

        }
    }.execute();
}