0

最初に、このコミュニティで 1 日私を助けてくれたすべての人に感謝したいと思います。

アクティビティに Listview アイテム (サーバーからダウンロード) を読み込もうとしています。私は GingerBread を使用しているため、AsyncTask を使用せずに実行しようとしましたが、完全に機能します。

AsyncTask で実行しようとすると、リストはまだ空です。また、一部を DoInBackground から onPostExecute に移動しようとしましたが、何も変わりませんでした。

これは私のコードです(2番目の回答後に更新)

MAIN



import java.util.ArrayList;
import java.util.HashMap;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;



import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

public class StudentMSG extends ListActivity {
    // url to make request
    private static String url = "http://www.xxxxxxxxxxxxx?requsted=xxxxxxxxx";
    // JSON Node names
    private static final String TAG_CONTACTS = "contacts";
    private static final String TAG_ID = "message_id";
    private static final String TAG_NAME = "sender_id";
    private static final String TAG_EMAIL = "title";
    private static final String TAG_ADDRESS = "message_id";
    private static final String TAG_GENDER = "READ";
    private static final String TAG_PHONE = "message_id";
    private static final String TAG_PHONE_MOBILE = "message_id";
    private static final String TAG_PHONE_HOME = "message_id";
    private static final String TAG_PHONE_OFFICE = "message_id";
    ListView lv;
    ArrayList<HashMap<String, String>> contactList ;
    JSONObject json ;
    ListAdapter adapter;
    // contacts JSONArray
    JSONArray contacts = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        load task=new load();
        task.execute();





    }



    public class load extends AsyncTask<Void, Void , Void>
    {
        @Override
        protected Void doInBackground(Void... params) {

            // Hashmap for ListView
            contactList = new ArrayList<HashMap<String, String>>();

            // Creating JSON Parser instance
            JSONParser jParser = new JSONParser();

            // getting JSON string from URL
             json = jParser.getJSONFromUrl(url);
                try {
                    contacts = json.getJSONArray(TAG_CONTACTS);
                // looping through All Contacts
                for(int i = 0; i < contacts.length(); i++){
                    JSONObject c = contacts.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_ID);
                    String name = c.getString(TAG_NAME);
                    String email = c.getString(TAG_EMAIL);
                    String address = c.getString(TAG_ADDRESS);
                    String gender = c.getString(TAG_GENDER);

                    // Phone number is agin JSON Object


                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_ID, id);
                    map.put(TAG_NAME, name);
                    map.put(TAG_EMAIL, email);
                    map.put(TAG_GENDER, gender);


                    // adding HashList to ArrayList
                    contactList.add(map);
                }
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            return null;



        }
        protected void onPostExecute() {

            String[] s = { TAG_NAME, TAG_EMAIL , TAG_GENDER};
            int[] n = {R.id.name, R.id.email , R.id.mobile };
          adapter = new SimpleAdapter(StudentMSG.this, contactList,R.layout.list_item,s,n );
            setListAdapter(adapter);
    }
}
}

これが JSON パーサー クラスです

import java.io.BufferedReader;
import java.io.IOException;
import java.io.InputStream;
import java.io.InputStreamReader;
import java.io.UnsupportedEncodingException;

import org.apache.http.HttpEntity;
import org.apache.http.HttpResponse;
import org.apache.http.client.ClientProtocolException;
import org.apache.http.client.methods.HttpPost;
import org.apache.http.impl.client.DefaultHttpClient;
import org.json.JSONException;
import org.json.JSONObject;

import android.util.Log;

public class JSONParser {

    static InputStream is = null;
    static JSONObject jObj = null;
    static String json = "";

    // constructor
    public JSONParser() {

    }

    public JSONObject getJSONFromUrl(String url) {

        // Making HTTP request
        try {
            // defaultHttpClient
            DefaultHttpClient httpClient = new DefaultHttpClient();
            HttpPost httpPost = new HttpPost(url);

            HttpResponse httpResponse = httpClient.execute(httpPost);
            HttpEntity httpEntity = httpResponse.getEntity();
            is = httpEntity.getContent();           

        } catch (UnsupportedEncodingException e) {
            e.printStackTrace();
        } catch (ClientProtocolException e) {
            e.printStackTrace();
        } catch (IOException e) {
            e.printStackTrace();
        }
        //"ISO-8859-1,utf-8;q=0.7,*;q=0.7"
        //"iso-8859-1"
        try {
            BufferedReader reader = new BufferedReader(new InputStreamReader(
                    is, "utf-8"), 8);
            StringBuilder sb = new StringBuilder();
            String line = null;
            while ((line = reader.readLine()) != null) {
                sb.append(line + "\n");
            }
            is.close();
            json = sb.toString();
        } catch (Exception e) {
            Log.e("Buffer Error", "Error converting result " + e.toString());
        }

        // try parse the string to a JSON object
        try {
            jObj = new JSONObject(json);
        } catch (JSONException e) {
            Log.e("JSON Parser", "Error parsing data " + e.toString());
        }

        // return JSON String
        return jObj;

    }
}

よろしくお願いします。

4

4 に答える 4

1
replace ur code by this=
import java.util.ArrayList;
import java.util.HashMap;

import org.json.JSONArray;
import org.json.JSONException;
import org.json.JSONObject;



import android.app.Activity;
import android.app.ListActivity;
import android.content.Intent;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.view.View;
import android.widget.AdapterView;
import android.widget.AdapterView.OnItemClickListener;
import android.widget.ListAdapter;
import android.widget.ListView;
import android.widget.ProgressBar;
import android.widget.SimpleAdapter;
import android.widget.TextView;
import android.widget.Toast;

public class StudentMSG extends ListActivity {
    // url to make request
    private static String url = "XXXXXXXXXXXXXXXXXXXX/json.php";
    // JSON Node names
    private static final String TAG_CONTACTS = "contacts";
    private static final String TAG_ID = "message_id";
    private static final String TAG_NAME = "sender_id";
    private static final String TAG_EMAIL = "title";
    private static final String TAG_ADDRESS = "message_id";
    private static final String TAG_GENDER = "READ";
    private static final String TAG_PHONE = "message_id";
    private static final String TAG_PHONE_MOBILE = "message_id";
    private static final String TAG_PHONE_HOME = "message_id";
    private static final String TAG_PHONE_OFFICE = "message_id";
    ListView lv;
    ArrayList<HashMap<String, String>> contactList ;
    JSONObject json ;
    ListAdapter adapter;
    // contacts JSONArray
    JSONArray contacts = null;
    @Override
    public void onCreate(Bundle savedInstanceState) {
        super.onCreate(savedInstanceState);
        setContentView(R.layout.main);
        load task=new load();
        task.execute();





    }



    public class load extends AsyncTask<Void, Void , Void>
    {
        @Override
        protected Void doInBackground(Void... params) {

            // Hashmap for ListView
            contactList = new ArrayList<HashMap<String, String>>();

            // Creating JSON Parser instance
            JSONParser jParser = new JSONParser();

            // getting JSON string from URL
             json = jParser.getJSONFromUrl(url);
                try {
                    contacts = json.getJSONArray(TAG_CONTACTS);
                // looping through All Contacts
                for(int i = 0; i < contacts.length(); i++){
                    JSONObject c = contacts.getJSONObject(i);

                    // Storing each json item in variable
                    String id = c.getString(TAG_ID);
                    String name = c.getString(TAG_NAME);
                    String email = c.getString(TAG_EMAIL);
                    String address = c.getString(TAG_ADDRESS);
                    String gender = c.getString(TAG_GENDER);

                    // Phone number is agin JSON Object


                    // creating new HashMap
                    HashMap<String, String> map = new HashMap<String, String>();

                    // adding each child node to HashMap key => value
                    map.put(TAG_ID, id);
                    map.put(TAG_NAME, name);
                    map.put(TAG_EMAIL, email);
                    map.put(TAG_GENDER, gender);


                    // adding HashList to ArrayList
                    contactList.add(map);
                }
                }
                catch (Exception e)
                {
                    e.printStackTrace();
                }
            return null;



        }
        protected void onPostExecute() {

            String[] s = { TAG_NAME, TAG_EMAIL , TAG_GENDER};
            int[] n = {R.id.name, R.id.email , R.id.mobile };
          adapter = new SimpleAdapter(StudentMSG.this, contactList,R.layout.list_item,s,n );
            setListAdapter(adapter);

    }
}
于 2012-10-06T08:27:03.000 に答える
0

このチュートリアルは、私が何を意味しているのかを示しています..http : //www.androidhive.info/2012/05/how-to-connect-android-with-php-mysql/すべての参加者に感謝します..

于 2012-10-06T18:30:41.737 に答える
0

あなたの投稿で Execute メソッド:

protected void onPostExecute() {
    runOnUiThread(new Runnable() {
       public void run() {
             String[] s = { TAG_NAME, TAG_EMAIL , TAG_GENDER};
             int[] n = {R.id.name, R.id.email , R.id.mobile };
             adapter = new SimpleAdapter(StudentMSG.this, contactList,R.layout.list_item,s,n );
             setListAdapter(adapter);
}}};

それはそれがクラッシュするのを防ぎます。それが役立つことを願っています

于 2013-07-15T12:14:03.353 に答える
0

データを通知するためにArrayAdapterを使用する必要があるSimpleAdapterに通知することはできません...各リスト項目に異なるビューが必要な場合は、BaseAdapterを通過する必要があります

于 2012-10-06T07:19:32.317 に答える