Android ListView不显示

Question

在我的代码中，我从php页面获取JSON格式的数据，然后将它们放入由SQLite创建的本地数据库中，并且我想在ListView中显示结果。

MainActivity.java

package com.example.ismail.test; 


import android.database.Cursor; 
import android.database.sqlite.SQLiteDatabase; 
import android.database.sqlite.SQLiteStatement; 
    import android.os.AsyncTask; 
import android.support.v7.app.AppCompatActivity; 
    import android.os.Bundle; 

import android.widget.ListAdapter; 
import android.widget.ListView; 
import android.widget.SimpleAdapter; 

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

import java.io.InputStream; 
import java.io.InputStreamReader; 
import java.net.HttpURLConnection; 
import java.net.URL; 
import java.util.ArrayList; 
import java.util.HashMap; 



    public class MainActivity extends AppCompatActivity { 

SQLiteDatabase articlesDB; 
ArrayList<HashMap<String, String>> pharmatList = new ArrayList<HashMap<String, String>>(); 
ArrayList<String> titles = new ArrayList<String>(); 
ArrayList<String> adresses = new ArrayList<String>(); 
ArrayList<String> tels = new ArrayList<String>(); 
ListAdapter adapter; 
ArrayList<String> urls = new ArrayList<String>(); 

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    setContentView(R.layout.activity_main); 



    ListView listView = (ListView) findViewById(R.id.list_view); 
    adapter = new SimpleAdapter(
      MainActivity.this, pharmatList, 
      R.layout.list_item, new String[]{"title", "adress", "tel"}, new int[]{R.id.name, 
      R.id.adress, R.id.tel}); 
    listView.setAdapter(adapter); 

    /* listView.setOnItemClickListener(new AdapterView.OnItemClickListener() { 
     @Override 
     public void onItemClick(AdapterView<?> parent, View view, int position, long id) { 
      Intent i = new Intent(getApplicationContext(), ArticleActivity.class); 
      // i.putExtra("tel", urls.get(position)); 
      // i.putExtra("content", content.get(position)); 
      startActivity(i); 
     } 
    });*/ 

    articlesDB = this.openOrCreateDatabase("pharmacie", MODE_PRIVATE, null); 


    articlesDB.execSQL("CREATE TABLE IF NOT EXISTS pharmacie (pharmacieID INTEGER PRIMARY KEY, title VARCHAR, address VARCHAR, tel VARCHAR)"); 

    updateListView(); 

    DownloadTask task = new DownloadTask(); 

    try { 
        task.execute("http://www.pfefes.tk/Pharmacie/pharmacie%20de%20garde/Agdal.php"); 

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


public void updateListView() { 
    try { 

     Cursor c = articlesDB.rawQuery("SELECT * FROM pharmacie ORDER BY pharmacieID DESC", null); 

     int telIndex = c.getColumnIndex("tel"); 
     int adressIndex = c.getColumnIndex("address"); 
     int titleIndex = c.getColumnIndex("title"); 

     titles.clear(); 
     adresses.clear(); 
     tels.clear(); 

     if (c != null && c.moveToFirst()) { 
      do { 

       titles.add(c.getString(titleIndex)); 
       adresses.add(c.getString(adressIndex)); 
       tels.add(c.getString(telIndex)); 

      } while (c.moveToNext()); 
     } 

     c.close(); 
     // ((ListAdapter) .getAdapter()).notifyDataSetChanged(); 
    } catch (Exception e) { 
     e.printStackTrace(); 
    } 
} 


public class DownloadTask extends AsyncTask<String, Void, String> { 

    @Override 
    protected String doInBackground(String... urls) { 
     String result = ""; 
     URL url; 
     HttpURLConnection urlConnection = null; 

     try { 

      url = new URL(urls[0]); 
      urlConnection = (HttpURLConnection) url.openConnection(); 
      InputStream in = urlConnection.getInputStream(); 
      InputStreamReader reader = new InputStreamReader(in); 

      int data = reader.read(); 

      String pharmacieInfo = ""; 

      while (data != -1) { 
       char current = (char) data; 
       pharmacieInfo += current; 

       data = reader.read(); 
      } 

      JSONObject jsonObject = new JSONObject(pharmacieInfo); 

      JSONArray parentArray = jsonObject.getJSONArray("pharma"); 


      articlesDB.execSQL("DELETE FROM pharmacie"); 

      for (int i = 0; i < parentArray.length(); i++) { 
       JSONObject finalObject = parentArray.getJSONObject(i); 


       String pharmacieTitle = finalObject.getString("name"); 
       String pharmacieAdress = finalObject.getString("adress"); 
       String pharmacieTel = finalObject.getString("tel"); 


       int j = 1; 

       HashMap<String, String> pharmaciee = new HashMap<String, String>(); 

       pharmaciee.put("name", pharmacieTitle); 
       pharmaciee.put("adrerss", pharmacieAdress); 
       pharmaciee.put("tel", pharmacieTel); 

       pharmatList.add(pharmaciee); 

       String sql = "INSERT INTO pharmacie (pharmacieID, title, address, tel) VALUES (?, ?, ?, ?)"; 
       SQLiteStatement statement = articlesDB.compileStatement(sql); 

       String strI = "" + j; 

       int k = 0; 
       statement.bindString(1, strI); 
       statement.bindString(2, pharmatList.get(k).get("name")); 
       statement.bindString(3, pharmatList.get(k).get("adrerss")); 
       statement.bindString(4, pharmatList.get(k).get("tel")); 
       k++; 
       statement.execute(); 

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

     return result; 
    } 

    @Override 
    protected void onPostExecute(String s) { 
     super.onPostExecute(s); 

     updateListView(); 
    } 
    } 
} 

Activity_main

 <?xml version="1.0" encoding="utf-8"?> 
    <RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/activity_main" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
tools:context="com.example.ismail.test.MainActivity"> 

    <ListView 
    android:id="@+id/list_view" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content"/> 
    </RelativeLayout> 

list_item.xml

<?xml version="1.0" encoding="utf-8"?> 
    <LinearLayout 
xmlns:android="http://schemas.android.com/apk/res/android" 
android:orientation="vertical" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:padding="@dimen/activity_vertical_margin"> 

<TextView 
    android:id="@+id/name" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"/> 

<TextView 
    android:id="@+id/adress" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"/> 

<TextView 
    android:id="@+id/tel" 
    android:layout_width="match_parent" 
    android:layout_height="wrap_content"/> 

</LinearLayout> 

Answer 1

你应该添加的元素到pharmatList后打电话adapter.notifyDataSetChanged()。