【发布时间】：2017-04-02 04:35:03
【问题描述】：
在我的应用程序中，我可以获取 json 中的数据并将其显示在列表视图上就好了，但现在我想要过滤，我想要基于每个 json 对象“estado”的字段的 3 个不同的过滤器。
我在操作栏上有一个菜单，用户可以在其中单击过滤器。
我的方法：
对于每个菜单项，我使用android:onClick="doC" 执行了一个函数，每个菜单项都将整数“s”的值更改为 1、2 或 3，因此 AsyncTask 获取此数字并执行不同的任务以进行过滤。
public void doC(MenuItem item){
Toast.makeText(this, "Concluidas", Toast.LENGTH_LONG).show();
s = 1;
new GetObras().execute();
}
public void doA(MenuItem item){
Toast.makeText(this, "Aguardam Aprovação", Toast.LENGTH_LONG).show();
s = 2;
}
public void doR(MenuItem item){
Toast.makeText(this, "Recusadas", Toast.LENGTH_LONG).show();
s = 3;
}
为了接收，我将函数签名更改为：
protected Void doInBackground(Integer... integers) {
然后在 doInBackground 我有：
if (s == 0) {
// do this
if (s == 1) {
//do this
}
我没有收到任何错误，但在我点击过滤器后，他会显示进度动画，但列表视图中没有任何变化。
完整代码：
public class MainActivity extends ActionBarActivity implements SearchView.OnQueryTextListener{
private String TAG = MainActivity.class.getSimpleName();
private ProgressDialog pDialog;
private ListView list;
int s;
private static String url = "http://ploran.gear.host/scriptobras6.php";
ArrayList<HashMap<String, String>> obrasList;
ArrayList<HashMap<String, String>> concluidasList;
@Override
protected void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
obrasList = new ArrayList<HashMap<String, String>>();
concluidasList = new ArrayList<HashMap<String, String>>();
list = (ListView)findViewById(R.id.list1);
new GetObras().execute();
list.setOnItemClickListener(new AdapterView.OnItemClickListener() {
@Override
public void onItemClick(AdapterView<?> arg0, View view, int position,
long id) {
Log.e("item clicks", "selected: " + position);
Intent intent = new Intent (MainActivity.this, DetailsActivity.class);
intent.putExtra("id", obrasList.get(position).get("Id"));
intent.putExtra("nomeobra", obrasList.get(position).get("nomeObra"));
intent.putExtra("idCliente", obrasList.get(position).get("idCliente"));
intent.putExtra("dataplevantamento", obrasList.get(position).get("DataLevantamento"));
intent.putExtra("datarlevantamento", obrasList.get(position).get("DataRealizacao"));
intent.putExtra("estado", obrasList.get(position).get("Estado"));
intent.putExtra("DataRMateriais", obrasList.get(position).get("DataRMateriais"));
intent.putExtra("DataInicioObra", obrasList.get(position).get("DataInicioObra"));
intent.putExtra("DataConclusao", obrasList.get(position).get("DataConclusao"));
intent.putExtra("DataVestoria\"", obrasList.get(position).get("DataVestoria"));
intent.putExtra("Obs", obrasList.get(position).get("Obs"));
intent.putExtra("Prompor", obrasList.get(position).get("Prompor"));
intent.putExtra("Levantpor", obrasList.get(position).get("Levantpor"));
intent.putExtra("executpor", obrasList.get(position).get("executpor"));
startActivity(intent);
}
});
}
private class GetObras extends AsyncTask<Integer, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Showing progress dialog
pDialog = new ProgressDialog(MainActivity.this);
pDialog.setMessage("Por favor aguarde ...");
pDialog.setCancelable(false);
pDialog.show();
}
@Override
protected Void doInBackground(Integer... integers) {
HttpHandler sh = new HttpHandler();
// Making a request to url and getting response
String jsonStr = sh.makeServiceCall(url);
Log.e(TAG, "Response from url: " + jsonStr);
JSONArray obras = null;
try {
obras = new JSONArray(jsonStr);
} catch (JSONException e) {
e.printStackTrace();
}
if (s == 0) {
if (jsonStr != null) {
try {
//JSONObject jsonObj = new JSONObject(jsonStr);
// Getting JSON Array node
//JSONArray obras = jsonObj.getJSONArray("obras");
// looping through All
for (int i = 0; i < obras.length(); i++) {
JSONObject c = obras.getJSONObject(i);
String id = c.getString("Id");
String nomeObra = c.getString("NomeObra");
String idCliente = c.getString("idCliente");
String DataLevantamento = c.getString("DataPLevantamento");
String DataRealizacao = c.getString("DataRLevantamento");
String Estado = c.getString("Estado");
String DataMateriais = c.getString("DataRMateriais");
String DataInicioObra = c.getString("DataInicioObra");
String DataConclusao = c.getString("DataConclusao");
String DataVestoria = c.getString("DataVestoria");
String Obs = c.getString("Obs");
String Prompor = c.getString("Prompor");
String Levantpor = c.getString("Levantpor");
String executpor = c.getString("executpor");
// tmp hash map for single contact
HashMap<String, String> obra = new HashMap<>();
// adding each child node to HashMap key => value
obra.put("Id", id);
obra.put("nomeObra", nomeObra);
obra.put("idCliente", idCliente);
obra.put("DataLevantamento", DataLevantamento);
obra.put("DataRealizacao", DataRealizacao);
obra.put("Estado", Estado);
obra.put("DataMateriais", DataMateriais);
obra.put("DataIncioObra", DataInicioObra);
obra.put("DataConclusao", DataConclusao);
obra.put("DataVestoria", DataVestoria);
obra.put("Obs", Obs);
obra.put("Prompor", Prompor);
obra.put("Levantpor", Levantpor);
obra.put("executpor", executpor);
// adding contact to contact list
obrasList.add(obra);
}
} catch (final JSONException e) {
Log.e(TAG, "Json parsing error: " + e.getMessage());
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Json parsing error: " + e.getMessage(),
Toast.LENGTH_LONG)
.show();
}
});
}
} else {
Log.e(TAG, "Couldn't get json from server.");
runOnUiThread(new Runnable() {
@Override
public void run() {
Toast.makeText(getApplicationContext(),
"Couldn't get json from server. Check LogCat for possible errors!",
Toast.LENGTH_LONG)
.show();
}
});
}
}
if ( s == 1) {
JSONObject object = null;
for (int i = 0; i < obras.length(); i++) {
try {
object = obras.getJSONObject(i);
} catch (JSONException e) {
e.printStackTrace();
}
try {
if (object.getString("Estado") == "Obra Concluída") {
JSONObject c = obras.getJSONObject(i);
String id = c.getString("Id");
String nomeObra = c.getString("NomeObra");
String idCliente = c.getString("idCliente");
String DataLevantamento = c.getString("DataPLevantamento");
String DataRealizacao = c.getString("DataRLevantamento");
String Estado = c.getString("Estado");
String DataMateriais = c.getString("DataRMateriais");
String DataInicioObra = c.getString("DataInicioObra");
String DataConclusao = c.getString("DataConclusao");
String DataVestoria = c.getString("DataVestoria");
String Obs = c.getString("Obs");
String Prompor = c.getString("Prompor");
String Levantpor = c.getString("Levantpor");
String executpor = c.getString("executpor");
// tmp hash map for single contact
HashMap<String, String> obra = new HashMap<>();
// adding each child node to HashMap key => value
obra.put("Id", id);
obra.put("nomeObra", nomeObra);
obra.put("idCliente", idCliente);
obra.put("DataLevantamento", DataLevantamento);
obra.put("DataRealizacao", DataRealizacao);
obra.put("Estado", Estado);
obra.put("DataMateriais", DataMateriais);
obra.put("DataIncioObra", DataInicioObra);
obra.put("DataConclusao", DataConclusao);
obra.put("DataVestoria", DataVestoria);
obra.put("Obs", Obs);
obra.put("Prompor", Prompor);
obra.put("Levantpor", Levantpor);
obra.put("executpor", executpor);
// adding contact to contact list
obrasList.add(obra);
}
} catch (JSONException e) {
e.printStackTrace();
}
}
}
return null;
}
@Override
protected void onPostExecute (Void result){
super.onPostExecute(result);
// Dismiss the progress dialog
if (pDialog.isShowing())
pDialog.dismiss();
/**
* Updating parsed JSON data into ListView
* */
ListAdapter adapter = new SimpleAdapter(
MainActivity.this, obrasList,
R.layout.list_item, new String[]{"nomeObra", "idCliente",
"Estado"}, new int[]{R.id.name,
R.id.email, R.id.mobile});
list.setAdapter(adapter);
if(pDialog.isShowing()) { pDialog.hide(); }
}
}
List<String> cities;
@Override
public boolean onCreateOptionsMenu(Menu menu) {
getMenuInflater().inflate(R.menu.options, menu);
return true;
}
@Override
public boolean onQueryTextSubmit(String query) {
// User pressed the search button
return false;
}
@Override
public boolean onQueryTextChange(String newText) {
// User changed the text
return false;
}
public void doC(MenuItem item){
Toast.makeText(this, "Concluidas", Toast.LENGTH_LONG).show();
s = 1;
new GetObras().execute();
}
public void doA(MenuItem item){
Toast.makeText(this, "Aguardam Aprovação", Toast.LENGTH_LONG).show();
s = 2;
}
public void doR(MenuItem item){
Toast.makeText(this, "Recusadas", Toast.LENGTH_LONG).show();
s = 3;
}
}
【问题讨论】：