我想在我的应用程序中使用搜索参数在列表视图中显示MySql中的数据。 我已经成功了，但我遇到的问题是，每次按下搜索按钮两次，两组结果数据都显示在ListView中，而我只想显示最新的结果集。
这是我正在使用的代码：
public class ListPerusahaan extends ListActivity {
/** Called when the activity is first created. */
private static final String TAG_ID = "id";
private static final String TAG_NAMA = "nama_perusahaan";
private static final String TAG_PEKERJAAN = "pekerjaan";
private static final String TAG_ALAMAT= "alamat";
private static final String TAG_DEADLINE = "deadline";
EditText keyword; Button search; private ProgressDialog pDialog; ArrayList<HashMap<String, String>> DataList; // JSONArray perusahaan = null;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.listperusahaan);
keyword=(EditText)findViewById(R.id.Editsearch);
search=(Button)findViewById(R.id.search);
DataList = new ArrayList<HashMap<String, String>>();
search.setOnClickListener(new View.OnClickListener()
{
@Override public void onClick(View v) {
// TODO Auto-generated method stub
if (keyword.getText().toString().length() == 0 ) {
Toast toast = Toast.makeText(getApplicationContext(),"Please enter your keyword", Toast.LENGTH_SHORT);
toast.setGravity(Gravity.CENTER_VERTICAL|Gravity.CENTER_HORIZONTAL, 0, 0);
toast.show();
}
else {
new searchData().execute();
}
}
});
}
@SuppressLint("NewApi") public class searchData extends AsyncTask<Void, Void, Void>
{
/**
* Before starting background thread Show Progress Dialog
* */
@Override
protected void onPreExecute() {
super.onPreExecute();
pDialog = new ProgressDialog(ListPerusahaan.this);
pDialog.setMessage("Loading ...");
pDialog.setIndeterminate(false);
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// TODO Auto-generated method stub
// ArrayList<HashMap<String, String>> mylist = new ArrayList<HashMap<String, String>>();
List<NameValuePair> paramemeter = new ArrayList<NameValuePair>();
paramemeter.add(new BasicNameValuePair("keyword", keyword.getText().toString()));
JSONObject json = JSONParser.getJSONFromUrl("http://10.0.2.2/appmysql/dataperusahaan.php", paramemeter);
try{
JSONArray perusahaan = json.getJSONArray("perusahaan");
if (perusahaan != null)
{
for(int i=0;i<perusahaan.length();i++){
// HashMap<String, String> map1 = new HashMap<String, String>();
JSONObject jsonobj = perusahaan.getJSONObject(i);
// Storing each json item in variable
String id = jsonobj.getString(TAG_ID);
String nama_perusahaan = jsonobj.getString(TAG_NAMA);
String pekerjaan = jsonobj.getString(TAG_PEKERJAAN);
String alamat = jsonobj.getString(TAG_ALAMAT);
String deadline = jsonobj.getString(TAG_DEADLINE);
// creating new HashMap
HashMap<String, String> map1 = new HashMap<String, String>();
// adding each child node to HashMap key => value
map1.put(TAG_ID, id);
map1.put(TAG_NAMA, nama_perusahaan);
map1.put(TAG_PEKERJAAN, pekerjaan);
map1.put(TAG_ALAMAT, alamat);
map1.put(TAG_DEADLINE, deadline);
// adding HashList to ArrayList
DataList.add(map1);
}
}
else {
Toast toast= Toast.makeText(getApplicationContext(), "No data found", Toast.LENGTH_SHORT);
toast.setGravity(Gravity.CENTER_VERTICAL|Gravity.CENTER_HORIZONTAL, 0, 0);
toast.show();
}
}
catch(JSONException e) {
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void result) {
// TODO Auto-generated method stub
pDialog.dismiss();
// updating UI from Background Thread
runOnUiThread(new Runnable() {
public void run() {
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
ListPerusahaan.this, DataList,R.layout.row,
new String[] { TAG_NAMA, TAG_PEKERJAAN, TAG_ALAMAT, TAG_DEADLINE },
new int[] { R.id.nama_perusahaan, R.id.pekerjaan, R.id.alamat,R.id.deadline});
// updating listview
setListAdapter(adapter);
final ListView lv = getListView();
lv.setTextFilterEnabled(true);
lv.setOnItemClickListener(new OnItemClickListener() {
public void onItemClick(AdapterView<?> parent, View view, int position, long id) {
/*
@SuppressWarnings("unchecked")
HashMap<String, String> o = (HashMap<String, String>) lv.getItemAtPosition(position);
Toast.makeText(ListPerusahaan.this, "Perusahaan '" + o.get("nama_perusahaan") + "' was clicked.", Toast.LENGTH_SHORT).show();
*/
// getting values from selected ListItem
String nama = ((TextView) view.findViewById(R.id.nama_perusahaan)).getText().toString();
String pekerjaan = ((TextView) view.findViewById(R.id.pekerjaan)).getText().toString();
String alamat = ((TextView) view.findViewById(R.id.alamat)).getText().toString();
String deadline = ((TextView) view.findViewById(R.id.deadline)).getText().toString();
// Starting new intent
Intent in = new Intent(getApplicationContext(), detail_lowongan.class);
in.putExtra(TAG_NAMA, nama);
in.putExtra(TAG_PEKERJAAN, pekerjaan);
in.putExtra(TAG_ALAMAT, alamat);
in.putExtra(TAG_DEADLINE, deadline);
startActivity(in);
}
});
}
});
}
}
}
答案 0 :(得分：0)
在for循环中填充之前清除ArrayList类型的DataList。
答案 1 :(得分：0)
编辑：在onclick上清除DataList
search.setOnClickListener(){
......
DataList.clear(); //in onclick method
}
我不确定您是否正在寻找此...但如果您不想在列表中允许重复，请尝试....
当列表中填写数据时
Set<type> set=new Hashset(yourlist);
ArrayList<type> nodupList=new ArrayList<type>();
noduplist.addAll(set);
使用这种方式，它将删除列表中的重复项
编辑： 试试这个
for for循环
Set<HashMap> set=new HashSet(DataList);
ArrayList<HashMap> nodupList=new ArrayList<HashMap>();
nodupList.addAll(set);
DataList.clear();
DataList.addAll(nodupList);
试试它可以帮到你