android setAdapter不會觸發getView或不會生成ListView

Question

問過多次，但我無法在自己的代碼中找到問題。

作爲其他人，我有一個ArrayList，我需要顯示它。

問題是ListView在活動啓動時不可見，我不知道爲什麼。

這裏是我的代碼：

佈局：activity_dashboard_screen.xml

<TableLayout xmlns:android="http://schemas.android.com/apk/res/android" 
xmlns:tools="http://schemas.android.com/tools" 
android:id="@+id/ly_dashboard" 
android:layout_width="match_parent" 
android:layout_height="match_parent" 
android:paddingBottom="@dimen/activity_vertical_margin" 
android:paddingLeft="@dimen/activity_horizontal_margin" 
android:paddingRight="@dimen/activity_horizontal_margin" 
android:paddingTop="@dimen/activity_vertical_margin" 
tools:context="com.ciroreed.war_horizon.ui.Dashboard_screen" > 

<TextView 
    android:id="@+id/tv_dashboard_display_username" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:text="username" 
    tools:ignore="HardcodedText" /> 

<TableRow 
    android:id="@+id/row_dashboard_1" 
    android:layout_width="wrap_content" 
    android:layout_height="wrap_content" 
    android:gravity="end" > 

</TableRow> 

<TableRow 
    android:id="@+id/row_dashboard_2" 
    android:layout_width="fill_parent" 
    android:layout_height="match_parent" > 

    <ListView 
     android:id="@+id/lv_dashboard_matchlist" 
     android:layout_width="fill_parent" 
     android:layout_height="match_parent" /> 

</TableRow> 

自定義類，它擴展BaseAdapter：MatchAdapter.java

package com.ciroreed.war_horizon; 

import java.util.ArrayList; 

import android.content.Context; 
import android.util.Log; 
import android.view.LayoutInflater; 
import android.view.View; 
import android.view.ViewGroup; 
import android.widget.BaseAdapter; 
import android.widget.TextView; 
import android.widget.TwoLineListItem; 

import com.ciroreed.war_horizon.data.Match; 

public class MatchAdapter extends BaseAdapter { 

    private Context con; 
    private ArrayList<Match> MATCHLIST; 


    public MatchAdapter(Context appcontext, ArrayList<Match> matchlist){ 
     con = appcontext; 
     MATCHLIST = matchlist; 

    } 

.............. 

    @Override 
    public View getView(int position, View convertView, ViewGroup parent) { 
     TwoLineListItem tll; 

     if (convertView == null) { 
      LayoutInflater inflater = (LayoutInflater) con 
        .getSystemService(Context.LAYOUT_INFLATER_SERVICE); 
      tll = (TwoLineListItem) inflater.inflate(
        android.R.layout.simple_list_item_2, parent); 
     } else { 
      tll = (TwoLineListItem) convertView; 
     } 

     TextView text1 = tll.getText1(); 
     TextView text2 = tll.getText2(); 

     text1.setText("VS "+MATCHLIST.get(position).getEnemy_name()); 
     text2.setText("turno: "+MATCHLIST.get(position).isPlayerTurn()); 

     return tll; 
    } 

} 

這裏是活動何時可以運行它：

package com.ciroreed.war_horizon.ui; 

import java.util.concurrent.ExecutionException; 

import org.json.JSONException; 

import android.app.Activity; 
import android.os.Bundle; 
import android.view.Menu; 
import android.view.MenuItem; 
import android.view.View; 
import android.view.View.OnClickListener; 
import android.widget.ListView; 
import android.widget.TextView; 
import android.widget.Toast; 

import com.ciroreed.war_horizon.Controller; 
import com.ciroreed.war_horizon.MatchAdapter; 
import com.ciroreed.war_horizon.R; 

public class Dashboard_screen extends Activity implements OnClickListener{ 

    private TextView tv_dashboard_username; 
    private ListView lv_dashboard_matchlist; 

    private MatchAdapter MATCHLIST_adapter; 

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

     init(); 
    } 

    private void init() { 
     // TODO Auto-generated method stub 
     tv_dashboard_username = (TextView)findViewById(R.id.tv_dashboard_display_username); 
     lv_dashboard_matchlist = (ListView)findViewById(R.id.lv_dashboard_matchlist); 


     try { 
      if(Controller.getCurrentMatches()){ 

       MATCHLIST_adapter = new MatchAdapter(getApplicationContext(), Controller.MATCHLIST);  

       Toast.makeText(getApplicationContext(), "Partidas cargadas correctamente", Toast.LENGTH_SHORT).show(); 
      }else{ 
       Toast.makeText(getApplicationContext(), "Error al cargar las partidas", Toast.LENGTH_SHORT).show(); 
      } 
     } catch (JSONException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (InterruptedException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } catch (ExecutionException e) { 
      // TODO Auto-generated catch block 
      e.printStackTrace(); 
     } 

     MATCHLIST_adapter.notifyDataSetChanged(); 
     lv_dashboard_matchlist.setAdapter(MATCHLIST_adapter); 
    } 

當我執行，..好吧，這不是主要活動。它運行正常，但和ArrayList<Match>包含一個元素（至少）..

請不要問有關以前的代碼是如何工作的，如「Controller.getCurrentMatches（）」 IE這個方法得到一個JSON從數據遠程服務器，除了相對於ListAdapter的代碼之前，其他所有代碼都已經過測試並正常工作。

Answer 1

從http://www.vogella.com/tutorials/AndroidListView/article.html

章：13教程：如何在ListView

package de.vogella.android.listactivity; 

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

import android.app.ListActivity; 
import android.os.Bundle; 
import android.widget.SimpleAdapter; 

public class MyTwoListItemsActivity extends ListActivity { 
    protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    ArrayList<Map<String, String>> list = buildData(); 
    String[] from = { "name", "purpose" }; 
    int[] to = { android.R.id.text1, android.R.id.text2 }; 

    SimpleAdapter adapter = new SimpleAdapter(this, list, 
     android.R.layout.simple_list_item_2, from, to); 
    setListAdapter(adapter); 
    } 

    private ArrayList<Map<String, String>> buildData() { 
    ArrayList<Map<String, String>> list = new ArrayList<Map<String, String>>(); 
    list.add(putData("Android", "Mobile")); 
    list.add(putData("Windows7", "Windows7")); 
    list.add(putData("iPhone", "iPhone")); 
    return list; 
    } 

    private HashMap<String, String> putData(String name, String purpose) { 
    HashMap<String, String> item = new HashMap<String, String>(); 
    item.put("name", name); 
    item.put("purpose", purpose); 
    return item; 
    } 

} 

這不是對這個問題的準確的反應顯示兩個項目，但它解決了我的問題。

Answer 2

你在你的適配器的getCount()中做了什麼？ 您應該返回一個大於0的值getCount()