Question

我试图这样做我有这个问题我试图获取列表视图中的选定位置的值，每次我把这行代码我有错误 “String name= (String) lv.getItemAtPosition(position);” 在方法yes（）; 我也试过用 “

HashMap<String, String> name = 
            (HashMap<String, String>) adapter.getItem(position);
String jok=name.get("joke");

“

但仍无法正常工作

这是我的代码

   package com.mall.our;

import java.util.ArrayList;
import java.util.HashMap;
import java.util.List;
import org.apache.http.NameValuePair;
import org.apache.http.message.BasicNameValuePair;
import org.json.JSONArray;
import org.json.JSONObject;
import android.app.ProgressDialog;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.SharedPreferences.Editor;
import android.os.AsyncTask;
import android.os.Bundle;
import android.preference.PreferenceManager;
import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.AdapterView;
import android.widget.BaseAdapter;
import android.widget.ListView;
import android.widget.AdapterView.OnItemClickListener;

import com.actionbarsherlock.app.SherlockListFragment;
import com.mall.first.CategoryListAdapter;
import com.mall.first.JSONParser;
import com.mall.first.Login;
import com.mall.first.R;





public class Friends extends SherlockListFragment {
    JSONParser jsonParser = new JSONParser();
    private static final String TAG_POSTS = "posts";
    public static final String TAG_ID = "id";
    public static final String TAG_NAME = "category";
    public static final String TAG_CATEGORIES_COUNT = "categories_count";
    public static final String TAG_CATEGORIES_LOGO = "categories_logo";

    private static final String URL_CATEGORY = "http://10.0.2.2/ochat/selectfriends.php";

        private BaseAdapter mAdapter;
        private ListView lv;
        SharedPreferences sp ;
    @Override
    public View onCreateView(LayoutInflater inflater, ViewGroup container,
            Bundle savedInstanceState) {
        View rootView = inflater.inflate(R.layout.friends, container, false);
        return rootView;
    }
     @Override 
        public void onActivityCreated(Bundle savedInstanceState) {  
            super.onActivityCreated(savedInstanceState);  
            lv = getListView();
            lv.setDivider(null);
            new LoadComments().execute(); 



     }

       class LoadComments extends AsyncTask<Void, Void, ArrayList<HashMap<String,String>>> {
            private ProgressDialog pDialog;
            @Override
            protected void onPreExecute() {
                super.onPreExecute();
                pDialog = new ProgressDialog(getActivity());

                pDialog.setIndeterminate(false);
                pDialog.setCancelable(true);

            }

            @Override
            protected ArrayList<HashMap<String, String>> doInBackground(Void... arg0) {

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

                SharedPreferences sp = PreferenceManager.getDefaultSharedPreferences(getActivity());
              String username = sp.getString("username", "anon");
                    List<NameValuePair> params = new ArrayList<NameValuePair>();
                    params.add(new BasicNameValuePair("username", username));
                  JSONObject json = jsonParser.makeHttpRequest(URL_CATEGORY, "POST",
                            params);

                  try {

                      JSONArray categories = json.getJSONArray(TAG_POSTS);
                      for (int i = 0; i < categories.length(); i++) {
                          String id = categories.getJSONObject(i).getString("TAG_ID");
                          String name = categories.getJSONObject(i).getString("TAG_NAME");
                          String songs_count = categories.getJSONObject(i).getString("TAG_CATEGORIES_COUNT");
                          String category_logo = categories.getJSONObject(i).getString("TAG_CATEGORIES_LOGO");

                          HashMap<String, String> map = new HashMap<String, String>();
                          map.put(TAG_ID, id);
                          map.put(TAG_NAME, name);
                          map.put(TAG_CATEGORIES_COUNT, songs_count);
                          map.put(TAG_CATEGORIES_LOGO, category_logo);

                          categoryList.add(map);
                      }
                  }catch (Throwable e){
                      e.printStackTrace();
                  }
                  return categoryList;
              }

            @Override
            protected void onPostExecute(ArrayList<HashMap<String, String>> result) {
                super.onPostExecute(result);

                mAdapter = new CategoryListAdapter(getActivity(),result);
                lv.setAdapter(mAdapter);
              yes();
            }

            private void yes() {
                lv.setOnItemClickListener(new OnItemClickListener() {

                    @Override
                    public void onItemClick(AdapterView<?> parent, View viewClicked,
                            int position, long id) {
                    String yy=  (String) lv.getItemAtPosition(position) ;                   
                                Intent i = new Intent(getActivity(),Chatting.class);    

                                startActivity(i);

                    }

                });
            }
        }
    }

这是我的错误

 02-09 19:12:31.280: E/AndroidRuntime(5915): java.lang.ClassCastException: java.lang.Integer cannot be cast to java.lang.String
    02-09 19:12:31.280: E/AndroidRuntime(5915):     at com.mall.our.Friends$LoadComments$1.onItemClick(Friends.java:128)
    02-09 19:12:31.280: E/AndroidRuntime(5915):     at android.widget.AdapterView.performItemClick(AdapterView.java:299)
    02-09 19:12:31.280: E/AndroidRuntime(5915):     at android.widget.AbsListView.performItemClick(AbsListView.java:1113)
    02-09 19:12:31.280: E/AndroidRuntime(5915):     at android.widget.AbsListView$PerformClick.run(AbsListView.java:2904)

CategoryListAdapter

package com.mall.first;

import java.util.ArrayList;

import java.util.HashMap;
import com.mall.our.Friends;
import com.squareup.picasso.Picasso;

import android.annotation.SuppressLint;
import android.content.Context;

import android.view.LayoutInflater;
import android.view.View;
import android.view.ViewGroup;
import android.widget.BaseAdapter;
import android.widget.ImageView;
import android.widget.TextView;

public class CategoryListAdapter extends BaseAdapter {
    private Context mContext;
    LayoutInflater inflater;
    private final ArrayList<HashMap<String, String>> urls;
    HashMap<String, String> resultp = new HashMap<String, String>();

    public static final String CATEGORY_LOGO_URL = "http://10.0.2.2/demi.jpg";

    public CategoryListAdapter(Context context,
            ArrayList<HashMap<String, String>> items) {
        mContext = context;
        urls = items;
    }

    @Override
    public int getCount() {
        return urls.size();
    }

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

    @Override
    public long getItemId(int position) {
        return getItem(position).hashCode();
    }

    @SuppressLint("ViewHolder")
    @Override
    public View getView(int position, View convertView, ViewGroup parent) {
        TextView category_name;
        ImageView category_logo;
        TextView item_count;
        TextView item_id;

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

        View view = inflater.inflate(R.layout.custom_list_category, parent,
                false);

        resultp = urls.get(position);

        category_name = (TextView) view.findViewById(R.id.timee);
        category_logo = (ImageView) view.findViewById(R.id.img_category_logo);
        item_count = (TextView) view.findViewById(R.id.songs_count);
        item_id = (TextView) view.findViewById(R.id.category_id);

        category_name.setText(resultp.get(Friends.TAG_NAME));
        item_count.setText(resultp.get(Friends.TAG_CATEGORIES_COUNT));
        item_id.setText(resultp.get(Friends.TAG_ID));

        // Picasso image loader library starts here
        Picasso.with(mContext)
                .load(resultp.get(Friends.TAG_CATEGORIES_LOGO)) // Photo URL
                .placeholder(R.drawable.placeholder) // This image will be displayed while photo URL is loading
                .error(R.drawable.error) // if error shows up during downloading
                .fit().centerCrop() // settings
                .into(category_logo); // we put it into our layout component (imageview)

        return view;
    }

}

Answer 1

问题出在getItem的{{1}}方法：

CategoryListAdapter

这是返回int的位置。你应该用

替换它

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

进行此更改后，代码

@Override
public Object getItem(int position) {
    return urls.get(position);
}

应该可以正常工作。

如何在SherlockListFragment中选择onitemclicklisterner

1 个答案: