ListView的数据没有显示在Android SDK中 [英] ListView data not showing on android sdk
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问题描述
我在做一个应用程序，我有一个名为SearchActivity的活动。我有两个自定义列表视图和一个效果很好。我的问题是与AdapterEventos使用的列表。当我启动应用程序没有出现在列表中。从这个列表中的数据是从邮政（DescarregarEventos法）加入，我认为这个问题是因为一个ArrayAdapter EVENTOS是空的。如果你看到我的code [1]，我打印之前这个名单的setAdapter返回空日志。是否有人知道我怎么能解决这个问题？
我已经看到POST请求返回的所有数据。
[1] http://pastebin.com/FZacCrHD
感谢
相关code：
公共类SearchActivity扩展ListActivity {
公众的ArrayList＆LT; Evento＆GT; EVENTOS =新的ArrayList＆LT; Evento＆GT;（）;
静态最后弦乐TAG =AsyncTaskParseJson.java;
静态最终的HttpClient HttpClient的=新DefaultHttpClient（）;公共类Evento {
公共字符串诺姆;
公共字符串地方;
公共字符串INICIO; 公共Evento（诺姆字符串，字符串地方，字符串INICIO）{
this.nome =诺姆;
this.local =地方;
this.inicio = INICIO;
} 公共字符串getNome（）{
返回诺姆;
} 公共无效setNome（字符串诺姆）{
this.nome =诺姆;
} 公共字符串中的getLocal（）{
返回地方;
} 公共无效SETLOCAL（字符串本地）{
this.local =地方;
} 公共字符串getInicio（）{
返回INICIO;
} 公共无效setInicio（字符串INICIO）{
this.inicio = INICIO;
} }
公共类AdapterEventos扩展ArrayAdapter＆LT; Evento＆GT; { 私人最终上下文的背景下;
私人最终的ArrayList＆LT; Evento＆GT; eventosArrayList; 公共AdapterEventos（上下文的背景下，ArrayList的＆LT; Evento＆GT; EVENTOS）{ 超（背景下，R.layout.listeventos，EVENTOS）; this.context =背景;
this.eventosArrayList = EVENTOS;
} 公共查看getViewEventos（INT位置，查看convertView，父母的ViewGroup）{ //创建气筒
LayoutInflater吹气=（LayoutInflater）context.getSystemService（Context.LAYOUT_INFLATER_SERVICE）; //从吹气获取rowView
查看LinhaEventoView = inflater.inflate（R.layout.listeventos，父母，假）; //从rowView文本视图
TextView的nomeView =（TextView中）LinhaEventoView.findViewById（R.id.tvNomeEvento）;
TextView的localView =（TextView中）LinhaEventoView.findViewById（R.id.tvLocalEvento）;
TextView的inicioView =（TextView中）LinhaEventoView.findViewById（R.id.tvInicioEvento）; //设置TextView的文本
nomeView.setText（eventosArrayList.get（位置）.getNome（））;
localView.setText（eventosArrayList.get（位置）.getLocal（））;
inicioView.setText（eventosArrayList.get（位置）.getInicio（））; //返回rowView
返回LinhaEventoView;
}
}
@覆盖
保护无效的onCreate（捆绑savedInstanceState）{super.onCreate（savedInstanceState）;
requestWindowFeature（Window.FEATURE_CUSTOM_TITLE）;
的setContentView（R.layout.search_activity）; 新DescarregarEventos（）执行（）;ListView控件ListEventos =（ListView控件）findViewById（R.id.listEventos）;
Log.d（EVENTOS，EVENTOS：+ EVENTOS）;
ListEventos.setAdapter（新AdapterEventos（这一点，EVENTOS））;
公共类DescarregarEventos扩展的AsyncTask＆LT;字符串，字符串，字符串＆GT; {
JSONArray dataJsonArr = NULL;保护字符串doInBackground（字符串... ARG）{
HttpPost httppost =新HttpPost（eventosUrl）;
字符串EVT = NULL;尝试{ // CriarparâmetrosØ段后。
清单＆LT;＆的NameValuePair GT; PARAMS =新的ArrayList＆LT;＆的NameValuePair GT;（）;
params.add（新BasicNameValuePair（EVENTOS，数据））; httppost.setEntity（新UrlEn codedFormEntity（PARAMS））; // ExecutarØ帖子。
ResponseHandler所＆LT;串GT; ResponseHandler所=新BasicResponseHandler（）;
EVT = httpclient.execute（httppost，ResponseHandler所）;}赶上（UnsupportedEncodingException五）{ Log.d（HTTP，ERRO一个ADICIONAR OSPARÂMETROSPARAØPOST EM \\DescarregarEventos（）\\）;
e.printStackTrace（）;}赶上（IOException异常五）{ Log.d（HTTP，ERRO EM \\DescarregarEventos（）\\）;
e.printStackTrace（）;
}返回EVT;}// Tratar一个resposta做邮政电子adicionar AO阵列respetivo。
公共无效onPostExecute（字符串EVT）{
尝试{
JSONArray E =新JSONArray（EVT）;
的for（int i = 0; I＆LT; E.length（）;我++）{
JSONObject的evento = E.getJSONObject（I）
eventos.add（新Evento（evento.getString（咔嗒），evento.getString（地点客户），evento.getString（data_inicio）））;
} }赶上（JSONException E）{
Log.d（HTTP，ERRO一个TRATAR OS EVENTOS EM \\DescarregarEventos（）\\ - \\onPostExecute（）\\）;
e.printStackTrace（）;
}}}}
解决方案
在第一次创建AdapterEventos的情况下，
AdapterEventos adapterEventos =新AdapterEventos（这一点，EVENTOS）;
ListEventos.setAdapter（adapterEventos）;
现在每次添加项目时间 EVENTOS 您必须通知新的数据已经到达适配器。
eventos.add（新Evento（evento.getString（诺姆），evento.getString（地点客户），evento.getString（data_inicio）））;
adapterEventos.notifyDataSetChanged（）;
I'm making an app and I have an activity called SearchActivity. I have two custom ListViews and one works well. My problem is the list used with AdapterEventos. When I start the app nothing appears in this list. The data from this list is added from a Post (DescarregarEventos method) and I think the problem is because the ArrayAdapter eventos is empty. If you see my code [1], the log that I print before the setAdapter of this list returns empty. Does somebody know how I can fix this? I'm already see that POST returns the all data requested.
[1] http://pastebin.com/FZacCrHD
Thanks
RELEVANT CODE:
public class SearchActivity extends ListActivity {
public ArrayList<Evento> eventos = new ArrayList<Evento>();
static final String TAG = "AsyncTaskParseJson.java";
static final HttpClient httpclient = new DefaultHttpClient();
public class Evento {
public String nome;
public String local;
public String inicio;
public Evento(String nome, String local, String inicio) {
this.nome = nome;
this.local = local;
this.inicio = inicio;
}
public String getNome() {
return nome;
}
public void setNome(String nome) {
this.nome = nome;
}
public String getLocal() {
return local;
}
public void setLocal(String local) {
this.local = local;
}
public String getInicio() {
return inicio;
}
public void setInicio(String inicio) {
this.inicio = inicio;
}
}
public class AdapterEventos extends ArrayAdapter<Evento> {
private final Context context;
private final ArrayList<Evento> eventosArrayList;
public AdapterEventos(Context context, ArrayList<Evento> eventos) {
super(context, R.layout.listeventos, eventos);
this.context = context;
this.eventosArrayList = eventos;
}
public View getViewEventos(int position, View convertView, ViewGroup parent) {
//Create inflater
LayoutInflater inflater = (LayoutInflater) context.getSystemService(Context.LAYOUT_INFLATER_SERVICE);
//Get rowView from inflater
View LinhaEventoView = inflater.inflate(R.layout.listeventos, parent, false);
//Get the text view from the rowView
TextView nomeView = (TextView) LinhaEventoView.findViewById(R.id.tvNomeEvento);
TextView localView = (TextView) LinhaEventoView.findViewById(R.id.tvLocalEvento);
TextView inicioView = (TextView) LinhaEventoView.findViewById(R.id.tvInicioEvento);
//Set the text for textView
nomeView.setText(eventosArrayList.get(position).getNome());
localView.setText(eventosArrayList.get(position).getLocal());
inicioView.setText(eventosArrayList.get(position).getInicio());
//return rowView
return LinhaEventoView;
}
}
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
requestWindowFeature(Window.FEATURE_CUSTOM_TITLE);
setContentView(R.layout.search_activity);
new DescarregarEventos().execute();
ListView ListEventos=(ListView)findViewById(R.id.listEventos);
Log.d("eventos","eventos: " + eventos);
ListEventos.setAdapter(new AdapterEventos(this, eventos));
public class DescarregarEventos extends AsyncTask<String, String, String> {
JSONArray dataJsonArr = null;
protected String doInBackground(String... arg) {
HttpPost httppost = new HttpPost(eventosUrl);
String evt = null;
try {
//Criar parâmetros para o Post.
List<NameValuePair> params = new ArrayList<NameValuePair>();
params.add(new BasicNameValuePair("eventos", "data"));
httppost.setEntity(new UrlEncodedFormEntity(params));
//Executar o Post.
ResponseHandler<String> responseHandler = new BasicResponseHandler();
evt = httpclient.execute(httppost, responseHandler);
} catch (UnsupportedEncodingException e) {
Log.d("HTTP","ERRO A ADICIONAR OS PARÂMETROS PARA O POST EM \"DescarregarEventos()\"");
e.printStackTrace();
} catch (IOException e) {
Log.d("HTTP", "ERRO EM \"DescarregarEventos()\"");
e.printStackTrace();
}
return evt;
}
// Tratar a resposta do Post e adicionar ao array respetivo.
public void onPostExecute(String evt) {
try {
JSONArray E = new JSONArray(evt);
for (int i = 0; i < E.length(); i++) {
JSONObject evento = E.getJSONObject(i);
eventos.add(new Evento(evento.getString("nome"),evento.getString("localizacao"),evento.getString("data_inicio")));
}
} catch (JSONException e) {
Log.d("HTTP","ERRO A TRATAR OS EVENTOS EM \"DescarregarEventos() \" - \"onPostExecute()\"");
e.printStackTrace();
}
}
}
}
解决方案
at first create instance of AdapterEventos,
AdapterEventos adapterEventos = new AdapterEventos(this, eventos);
ListEventos.setAdapter(adapterEventos );
now every time you add item to eventos you have to notify the adapter that new data has arrived.
eventos.add(new Evento(evento.getString("nome"),evento.getString("localizacao"),evento.getString("data_inicio")));
adapterEventos.notifyDataSetChanged();
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