我的代码存在问题。 在我的活动中，它打印一个具有空值的重复listView！我怎样才能改变这种行为呢？
在java文件中，连接有效，但我不明白为什么它会显示重复。
public class OlivetoEventi extends Activity {
// JSON Node names
private static final String TAG_EVENTI = "eventi";
private static final String TAG_TITOLO = "titolo";
private static final String TAG_DESC = "descrizione";
private static final String TAG_LUOGO = "luogo";
private static final String TAG_DATA = "data";
// private static final String TAG_LINK = "link";
// message intent
public final static String EXTRA_MESSAGE = "com.aljacket.appcomuneoc.MESSAGE";
// products JSONArray
JSONArray products = null;
String[] titolo = new String[100];
String[] data = new String[100];
String[] luogo = new String[100];
String[] descrizione = new String[200];
String[] newDate = new String[100];
int lunghezza;
InputStream is = null;
String result = null;
StringBuilder sb = null;
JSONArray jArray;
TextView event;
ImageButton ImBu[] = new ImageButton[100];
ImageButton back,home;
ArrayList<HashMap<String, String>> oslist = new ArrayList<HashMap<String, String>>();
ListView list;
ArrayAdapter<String> listAdapter;
getEventi mTask;
ConnectivityManager cm;
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listview_eventi);
list = (ListView) findViewById(R.id.eventiListView);
if(isOnline()){
mTask = new getEventi();
mTask.execute();
}
else{
Toast.makeText(getApplicationContext(), "Hai bisogno di una connessione dati o di una rete WI-FI " +
"per poter leggere le ultime News",
Toast.LENGTH_LONG).show();
}
back = (ImageButton) findViewById(R.id.imageRetry);
back.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
// TODO Auto-generated method stub
retry(v);
}
});
atHomeButton();
new getEventi().execute();
}
class getEventi extends AsyncTask<Void, Void, Void> {
private ProgressDialog pDialog;
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(OlivetoEventi.this);
pDialog.setMessage("Caricamento ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(true);
pDialog.show();
}
/**
* Getting product details in background thread
* */
protected Void doInBackground(Void... params) {
connect();
return null;
}
protected void onPostExecute(Void result) {
pDialog.dismiss();
for (int i = 0; i < lunghezza; i++) {
SimpleDateFormat sdf = new SimpleDateFormat("yyyy-mm-dd");
Date testDate = null;
try {
testDate = sdf.parse(data[i]);
} catch (Exception ex) {
ex.printStackTrace();
}
SimpleDateFormat formatter = new SimpleDateFormat("dd-mm-yyyy");
newDate[i] = formatter.format(testDate);
// Adding value HashMap key => value
HashMap<String, String> eventiHM = new HashMap<String, String>();
eventiHM.put("titolo", titolo[i]);
eventiHM.put("descrizione", descrizione[i]);
eventiHM.put("data", newDate[i]);
eventiHM.put("luogo", luogo[i]);
//confrontare ed eliminare gli hashmap con valori uguali
// for(Object key1:eventiHM.keySet()){
//
// for(Object key2:eventiHM.keySet()){
// if(!key1.toString().equals(key2.toString())){
// String x=eventiHM.get(key1);
// String y=eventiHM.get(key2);
// if(x.equals(y)){
// eventiHM.remove(key2);
// }
// }
//
// }
// }
oslist.add(eventiHM);
ListAdapter eventiAdapter = new SimpleAdapter(OlivetoEventi.this,
oslist, R.layout.row, new String[] { "titolo", "data" },
new int[] { R.id.rowTextView, R.id.rowEventiData });
list.setAdapter(eventiAdapter);
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> parent, View view,
int position, long id) {
// TODO Auto-generated method stub
// Toast.makeText(OlivetoEventi.this, "You Clicked at "+
// oslist.get(position).get("luogo"),
// Toast.LENGTH_SHORT).show();
//
Intent ev_intent = new Intent(OlivetoEventi.this,
ShowEventActivity.class);
String message = titolo[position] + "§"
+ newDate[position] + "§"
+ descrizione[position] + "§" + luogo[position];
ev_intent.putExtra(EXTRA_MESSAGE, message);
startActivity(ev_intent);
}
});
}
}
}
private void connect() {
try {
DefaultHttpClient client = new DefaultHttpClient();
HttpGet request = new HttpGet(
"url");
HttpResponse response = client.execute(request);
HttpEntity entity = response.getEntity();
is = entity.getContent();
Log.d("HTTP", "collegamento effettuato");
// convertire response a stringa
try {
BufferedReader reader = new BufferedReader(
new InputStreamReader(is, "iso-8859-1"), 8);
sb = new StringBuilder();
sb.append(reader.readLine() + "\n");
String line = "0";
while ((line = reader.readLine()) != null) {
sb.append(line + "\n");
}
is.close();
result = sb.toString();
// Log.d("CONVERTING", "conversione effettuata: " + result);
} catch (Exception e) {
Log.d("log_tag", "Error converting result: " + e.toString());
}
// recupero dati
runOnUiThread(new Runnable() {
public void run() {
Log.d("RUN", "entra");
try {
JSONObject jsonA = new JSONObject(result);
JSONArray jArray = jsonA.getJSONArray(TAG_EVENTI);
System.out
.println("*****JARRAY*****" + jArray.length());
lunghezza = jArray.length();
for (int i = 0; i < jArray.length(); i++) {
JSONObject json_data = jArray.getJSONObject(i);
titolo[i] = json_data.getString(TAG_TITOLO);
luogo[i] = json_data.getString(TAG_LUOGO);
data[i] = json_data.getString(TAG_DATA);
descrizione[i] = json_data.getString(TAG_DESC);
}
} catch (JSONException e1) {
Log.d("DATA", "no data found");
}
}
});
} catch (ClientProtocolException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
} catch (IOException e) {
Log.d("HTTPCLIENT", e.getLocalizedMessage());
}
}
public void onBackPressed() {
finish();
}
public void atHomeButton() {
home = (ImageButton) findViewById(R.id.imageHome);
home.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View arg0) {
Intent intent = new Intent(OlivetoEventi.this, HomeActivity.class);
startActivity(intent);
}
});
}
public void retry(View v){
onback();
}
public void onback(){
finish();
}
public boolean isOnline() {
cm = (ConnectivityManager) getSystemService(Context.CONNECTIVITY_SERVICE);
NetworkInfo netInfo = cm.getActiveNetworkInfo();
if (netInfo != null && netInfo.isConnectedOrConnecting()) {
return true;
}
return false;
}
}
row.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="match_parent"
android:layout_height="match_parent"
android:orientation="horizontal"
android:background="@android:color/darker_gray"
>
<TextView
android:id="@+id/rowTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:paddingBottom="20dp"
android:textSize="25sp"
/>
<TextView
android:id="@+id/rowEventiData"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:layout_alignParentBottom="true"
android:textSize="15sp"
/>
<ImageView
android:src="@drawable/list_item_arrow"
android:layout_width="20dp"
android:layout_height="20dp"
android:layout_alignParentRight="true"
android:layout_centerVertical="true"
/>
</RelativeLayout>
listview.xml：
<?xml version="1.0" encoding="utf-8"?>
<RelativeLayout xmlns:android="http://schemas.android.com/apk/res/android"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:orientation="horizontal" >
<TextView
android:id="@+id/rowTextView"
android:layout_width="match_parent"
android:layout_height="wrap_content"
android:drawableLeft="@drawable/oliveto"
android:gravity="center"
android:paddingBottom="20dp"
android:text="Eventi Olivetani"
android:textSize="25sp" />
<ListView
android:id="@+id/eventiListView"
android:layout_width="fill_parent"
android:layout_height="fill_parent"
android:layout_below="@+id/rowTextView"
android:layout_above="@+id/footer">
</ListView>
<RelativeLayout
android:id="@+id/footer"
android:layout_width="match_parent"
android:layout_height="50dp"
android:layout_alignParentBottom="true"
android:layout_alignParentLeft="true"
android:layout_alignParentRight="true"
android:background="#80C0C0C0" >
<ImageButton
android:id="@+id/imageRetry"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentLeft="true"
android:layout_centerVertical="true"
android:layout_marginLeft="34dp"
android:src="@drawable/reply" />
<ImageButton
android:id="@+id/imageHome"
android:layout_width="wrap_content"
android:layout_height="wrap_content"
android:layout_alignParentRight="true"
android:layout_alignTop="@+id/imageRetry"
android:layout_marginRight="38dp"
android:src="@drawable/home" />
</RelativeLayout>
</RelativeLayout>