Question

问了很多次但我在自己的代码中找不到问题。

和其他人一样，我有一个ArrayList，我需要显示它。

问题是当活动启动时ListView不可见，我不知道为什么。

这是我的代码：

布局：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>

扩展BaseAdapter的自定义类：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;
    }

}

以下是可以运行它的活动：

    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);
    }

当我执行时，......好吧，这不是主要活动。它按预期运行，但ArrayList<Match>包含一个元素（至少）..

请不要问前面的代码是如何工作的，如“Controller.getCurrentMatches（）”IE该方法从远程服务器获取带有数据的json，除了相对于ListAdapter的代码之前测试的所有其他内容并且工作正常。

Answer 1

您在适配器的getCount()中做了什么？你应该返回一个值＆gt; getCount()

中的0

Answer 2

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

章： 13。教程：如何在ListView中显示两个项目

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;
  }

}

这不是对此问题的准确回答，但它解决了我的问题。

android setAdapter不触发getView或不构建ListView

2 个答案: