java - 从惰性 ListView 适配器获取数据不起作用android

Question

我正在为我的 ListView 使用惰性列表适配器。我尝试通过复选框选择获取图像 url 和列表中的文本，但两者总是不规则地出现，但列表的位置正确。同时，当我按下第一个复选框时，它会选择所有复选框，当我选择第二个框时，甚至会选择所有复选框，下面是我的代码。任何人都可以指导为什么数据没有正确获取。

      class AllLiteratures extends AsyncTask<String, Void, String> {


    private ProgressDialog dialog = new ProgressDialog(LiteratureList.this);
    @Override
    public void onPreExecute() {
        if(litList == null) {

            // setup your dialog here
            dialog.setMessage("Loading...");
            dialog.setCancelable(false);
            dialog.show();
        }
    }
    @Override
    protected String doInBackground(String... arg0) {
        // TODO Auto-generated method stub
        String productConnect = GetStates();
        //set_orienation = getOrient.getOrientation();
        return productConnect;
    }

    private String GetStates() {
        // TODO Auto-generated method stub
           // Hashmap for ListView
        // Creating JSON Parser instance

        if(litList == null) { System.out.println("back");
        JSONParser jParser = new JSONParser(LiteratureList.this);
        try {
            json_literature = jParser.getJsonFromUrl("http://tsubaki.usawebdept.com/?type=listOfLiterature");
            if(json_literature!= null) {
                literature_list = json_literature.toString();
            }
        } catch (JSONException e1) {
            // TODO Auto-generated catch block
            e1.printStackTrace();
        }
        }
        return literature_list;
    }
    @SuppressLint("ShowToast")
    public void onPostExecute(String result) {
         System.out.println("result");
         if (result != "" && result != null) {
             dialog.dismiss();

             litList = new  ArrayList<HashMap<String,String>>();
                try {
                    // Getting Array of Contacts
                    us_literature_list = json_literature.getJSONArray("list");
                    lit_url = json_literature.getString("siteUrl")+"/";

                    // looping through All Contacts
                    System.out.println("Length"+us_literature_list.length());
                    for(int i = 0; i < us_literature_list.length(); i++){
                        JSONObject c = us_literature_list.getJSONObject(i);
                        // Storing each json item in variable
                        String name = c.getString(CATEGORY_NAME);
                        String image = c.getString(LARGE_IMAGE.replace(" ", "%20"));
                        String can_order = c.getString(CAN_ORDER);

                        // creating new HashMap
                        HashMap<String, String> map = new HashMap<String, String>();
                        // adding each child node to HashMap key => value
                        map.put(CATEGORY_NAME, name);
                        map.put(LARGE_IMAGE, lit_url +"/"+ image.replace(" ", "%20"));
                        map.put(CAN_ORDER,can_order);
                                // adding HashList to ArrayList
                        litList.add(map);

                    }
                } catch (JSONException e) {
                    e.printStackTrace();
                }
                System.out.println("List" +litList);
                lit_home=(ListView) findViewById(R.id.lit_home);
                lit_home.setScrollingCacheEnabled(true);
                lit_home.setFastScrollEnabled(true);
                literature_adapt=new LiteratureAdapter(LiteratureList.this, litList);
                lit_home.setAdapter(literature_adapt);

                OnItemClickListener listener = new OnItemClickListener() {
                    public void onItemClick(AdapterView<?> arg0, View arg1, int arg2, long arg3) {

                    }
                };  
                lit_home.setOnItemClickListener(listener);
     } else {
         if(literature_list != null) {
             Toast.makeText(LiteratureList.this, "No Data to Show!", 30).show();
         } else {
             Toast.makeText(LiteratureList.this, "Server is not responding!", 30).show();
         }
     }
    } 

}

//我的惰性适配器

     class LiteratureAdapter extends BaseAdapter {

private Activity activity;
private ArrayList<HashMap<String, String>> data;
LayoutInflater inflater=null;
public ProductImageLoader imageLoader; 
String adapter_for;
int loader1;
ViewHolder viewHolder;
public LiteratureAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
    activity = a;
    data=d;
    //get_orientation = orientation;
    inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
    imageLoader=new ProductImageLoader(activity.getApplicationContext());
}

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

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

public long getItemId(int position) {
    return position;
}
public class ViewHolder {
   TextView title;
   CheckBox check_lit;
   LinearLayout quantity_selection;
   ImageView thumb_image;
   HashMap<String, String> song;
   String can_order;
   EditText quantity_lit;
   String quantity;
   CheckBox cb;
  // RadioButton cb;
  }
public View getView(final int position, View convertView, ViewGroup parent) {
    View vi=convertView;
    viewHolder = new ViewHolder();
    if(convertView==null)
        vi = inflater.inflate(R.layout.literature_items_port, null);
        viewHolder.quantity_lit = (EditText)vi.findViewById(R.id.quantity_lit);
        viewHolder.quantity = viewHolder.quantity_lit.getText().toString(); 
        viewHolder.title = (TextView)vi.findViewById(R.id.catalog_name); // title
        viewHolder.quantity_selection = (LinearLayout)vi.findViewById(R.id.quantity_selection);
        viewHolder.check_lit = (CheckBox)vi.findViewById(R.id.check_lit);
        viewHolder.thumb_image=(ImageView)vi.findViewById(R.id.literature_image); // thumb image

        //ScrollView cat_scroll_list = (ScrollView)vi.findViewById(R.id.cat_scroll_list);
        viewHolder.song = new HashMap<String, String>();
        viewHolder.song = data.get(position);
        //data.add(viewHolder.song);
        viewHolder.title.setText(viewHolder.song.get(LiteratureList.CATEGORY_NAME));
        imageLoader.DisplayImage(viewHolder.song.get(LiteratureList.LARGE_IMAGE),loader1, viewHolder.thumb_image);
        viewHolder.thumb_image.setScaleType(ScaleType.FIT_XY);
        vi.setTag(viewHolder); 

        viewHolder.check_lit
        .setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

            @Override
            public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {
                Boolean flag = isChecked;    
                viewHolder.cb = (CheckBox) buttonView; 
                if(viewHolder.cb.isChecked()){      
                    //viewHolder.check_lit.setChecked(viewHolder.song.get(position));///move to here
                    System.out.println("Position"+literature_adapt.getItem(position));
                    System.out.println("Text"+ viewHolder.title.getText());
                    //System.out.println("Image"+ viewHolder.thumb_image.toString());
                    //System.out.println("Order"+ viewHolder.song.get(LiteratureList.CAN_ORDER));
                        //Toast.makeText(context, "Marked as Favorite Game!", 1).show();                  
                }
            }
        }); 
    return vi;
}
}

Answer 1

重构并修复适配器，这应该可以解决问题，您可能需要进行一些更改

class LiteratureAdapter extends BaseAdapter {

    private Activity activity;
    private ArrayList<HashMap<String, String>> data;
    LayoutInflater inflater=null;
    public ProductImageLoader imageLoader; 
    String adapter_for;
    int loader1;
    int selected = -1; // by default nothing is selected

    public LiteratureAdapter(Activity a, ArrayList<HashMap<String, String>> d) {
        activity = a;
        data=d;
        //get_orientation = orientation;
        inflater = (LayoutInflater)activity.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
        imageLoader=new ProductImageLoader(activity.getApplicationContext());
    }

    public int getCount() {
        if(null == data){ 
            return 0;
        }else{
            return data.size();
        }
    }

    public HashMap<String, String> getItem(int position) {
        if(null == data){
            return null;
        }else{
            return data.get(position);
        }
    }

    public long getItemId(int position) {
        return position;
    }
    public class ViewHolder {
       TextView title;
       CheckBox check_lit;
       LinearLayout quantity_selection;
       ImageView thumb_image;
       HashMap<String, String> song;
       String can_order;
       EditText quantity_lit;
       String quantity;
       CheckBox cb;
    }

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

        ViewHolder viewHolder = null;

        if(convertView==null){
            viewHolder = new ViewHolder();

            convertView = inflater.inflate(R.layout.literature_items_port, null);
            viewHolder.quantity_lit = (EditText)convertView.findViewById(R.id.quantity_lit);

            viewHolder.title = (TextView)convertView.findViewById(R.id.catalog_name); // title
            viewHolder.quantity_selection = (LinearLayout)convertView.findViewById(R.id.quantity_selection);
            viewHolder.check_lit = (CheckBox)convertView.findViewById(R.id.check_lit);
            viewHolder.thumb_image=(ImageView)convertView.findViewById(R.id.literature_image); // thumb image

            //ScrollView cat_scroll_list = (ScrollView)convertView.findViewById(R.id.cat_scroll_list);
            viewHolder.song = new HashMap<String, String>();
            viewHolder.check_lit.setOnCheckedChangeListener(new CompoundButton.OnCheckedChangeListener() {

                @Override
                public void onCheckedChanged(CompoundButton buttonView,boolean isChecked) {    

                    if(isChecked){                    
                        String sPos = (String)buttonView.getTag();
                        int iPos = Integer.parseInt(pos);
                        if(selected != iPos){
                            selected = iPos;
                            //new Item got selected do your work here
                            Toast.makeText(a.getApplicationContext(), "User selected: "+ iPos, Toast.LENGTH_LONG).show();
                            LiteratureAdapter.this.notifyDataSetChanged();
                        }
                    }
                }
            });
            convertView.setTag(viewHolder); 

        }else{
            viewHolder = (ViewHolder) convertView.getTag();
        }   
        //retain the checked state
        if(position == selected){
            viewHolder.check_lit.setChecked(true);
        }else{
            viewHolder.check_lit.setChecked(false); //needs to be reset
        }

        viewHolder.check_lit.setTag(""+position);

        viewHolder.song = getItem(position);

        viewHolder.title.setText(viewHolder.song.get(LiteratureList.CATEGORY_NAME));
        imageLoader.DisplayImage(viewHolder.song.get(LiteratureList.LARGE_IMAGE),loader1, viewHolder.thumb_image);
        viewHolder.thumb_image.setScaleType(ScaleType.FIT_XY);

        return convertView;
    }
}

我基本上保留了最后检查的位置，并在 getView 中检查相同的位置以相应地更新复选框。