在同一个 activity 中调用 Twoo AsyncTask
Call Twoo AsyncTask in the same activity
我正在使用 AsyncTask 从我的服务器 url 中拯救 json 数据。我不知道为什么，但有时运行良好，而其他应用程序则以错误结束。这是我的日志猫的错误：
01-30 22:28:00.998: E/AndroidRuntime(3404): FATAL EXCEPTION: AsyncTask #2
01-30 22:28:00.998: E/AndroidRuntime(3404): Process: my.package.com, PID: 3404
01-30 22:28:00.998: E/AndroidRuntime(3404): java.lang.RuntimeException: An error occured while executing doInBackground()
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask.done(AsyncTask.java:300)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.lang.Thread.run(Thread.java:841)
01-30 22:28:00.998: E/AndroidRuntime(3404): Caused by: java.lang.NullPointerException
01-30 22:28:00.998: E/AndroidRuntime(3404): at my.package.com.ProgramacionActivity$DownloadJSONdos.doInBackground(ProgramacionActivity.java:342)
01-30 22:28:00.998: E/AndroidRuntime(3404): at my.package.com.ProgramacionActivity$DownloadJSONdos.doInBackground(ProgramacionActivity.java:1)
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask.call(AsyncTask.java:288)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
01-30 22:28:00.998: E/AndroidRuntime(3404): ... 4 more
01-30 22:28:01.188: E/log_tag(3404): Error parsing data org.json.JSONException: End of input at character 0 of
有人能告诉我为什么这些应用程序有时运行良好而有时运行不佳吗？在我的 activity 中，我有两个这样调用的 AsyncTask：
new DownloadJSONdos().execute();
new DownloadJSON().execute();
我的 activity 代码：
public class ProgramacionActivity extends Fragment implements
AdapterView.OnItemSelectedListener{
ProgressDialog mProgressDialog;
private ViewPager mViewPager;
String idioma;
LinearLayout linear_marcador;
String results;
String jsonStr;
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
LazyAdapterHorariosLiga adapter;
ArrayList<HashMap<String, String>> arraylist;
ArrayList<String> elementos_marcador;
ArrayList<Proximo_Partido> elementos_proximos;
JSONArray eventos = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> eventosList;
ImageLoader imageLoader;
static final String TAG_ICONO_LOCAL= "icono_local";
static final String TAG_EQUIPO_LOCAL= "equipo_local";
static final String TAG_GOLES_LOCAL= "goles_local";
static final String TAG_ICONO_VISITANTE= "icono_visitante";
static final String TAG_EQUIPO_VISITANTE= "equipo_visitante";
static final String TAG_GOLES_VISITANTE= "goles_visitante";
static final String TAG_ESTADO= "estado";
static final String TAG_ESTADIO= "estadio";
static final String TAG_COMPETICION= "competicion";
TextView equipo_local, equipo_visitante, goles_local, goles_visitante, estado, estadio, competicion;
int i;
TextView competi_portada_uno, competi_portada_dos, competi_portada_tres, fecha1, fecha2, fecha3;
ImageView icono_local1, icono_local2, icono_local3,icono_visitante1, icono_visitante2, icono_visitante3;
ImageView icono_local, icono_visitante;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.programacion_main, container, false);
linear_marcador = (LinearLayout) v.findViewById(R.id.linear_marcador);
animate(linear_marcador).alpha(0).setDuration(0);
mViewPager = (ViewPager) v.findViewById(R.id.viewpager);
PagerTabStrip pagerTabStrip = (PagerTabStrip) v.findViewById(R.id.pagerTabStrip);
pagerTabStrip.setTabIndicatorColor(getResources().getColor(R.color.blanco));
equipo_local=(TextView) v.findViewById(R.id.eq_local);
equipo_visitante=(TextView) v.findViewById(R.id.eq_visitante);
goles_local=(TextView) v.findViewById(R.id.gol_local);
equipo_visitante=(TextView) v.findViewById(R.id.eq_visitante);
goles_visitante=(TextView) v.findViewById(R.id.gol_visitante);
estado=(TextView) v.findViewById(R.id.estado_parti);
estadio=(TextView) v.findViewById(R.id.estadiaco);
competicion=(TextView) v.findViewById(R.id.competicionaca);
icono_local=(ImageView) v.findViewById(R.id.icono_local);
icono_visitante=(ImageView) v.findViewById(R.id.icono_visitante);
icono_local1=(ImageView) v.findViewById(R.id.icono_local1);
icono_visitante1=(ImageView) v.findViewById(R.id.icono_visitante1);
icono_local2=(ImageView) v.findViewById(R.id.icono_local2);
icono_visitante2=(ImageView) v.findViewById(R.id.icono_visitante2);
icono_local3=(ImageView) v.findViewById(R.id.icono_local3);
icono_visitante3=(ImageView) v.findViewById(R.id.icono_visitante3);
competi_portada_uno=(TextView) v.findViewById(R.id.competi_portada1);
competi_portada_dos=(TextView) v.findViewById(R.id.competi_portada2);
competi_portada_tres=(TextView) v.findViewById(R.id.competi_portada3);
fecha1=(TextView) v.findViewById(R.id.fecha1);
fecha2=(TextView) v.findViewById(R.id.fecha2);
fecha3=(TextView) v.findViewById(R.id.fecha3);
Typeface font = Typeface.createFromAsset(getActivity().getAssets(),"fonts/Roboto-Thin.ttf");
Typeface font_dos = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Roboto-Medium.ttf");
equipo_local.setTypeface(font_dos);
equipo_visitante.setTypeface(font_dos);
estadio.setTypeface(font_dos);
competicion.setTypeface(font_dos);
goles_local.setTypeface(font);
goles_visitante.setTypeface(font);
competi_portada_uno.setTypeface(font_dos);
competi_portada_dos.setTypeface(font_dos);
competi_portada_tres.setTypeface(font_dos);
fecha1.setTypeface(font_dos);
fecha2.setTypeface(font_dos);
fecha3.setTypeface(font_dos);
new java.util.Timer().schedule(
new java.util.TimerTask() {
@Override
public void run() {
animate(linear_marcador).alpha(1).setDuration(1200);
}
},
2500
);
TitleAdapter titleAdapter = new TitleAdapter(getActivity().getSupportFragmentManager());
mViewPager.setAdapter(titleAdapter);
mViewPager.setCurrentItem(0);
mFlipper = ((ViewFlipper) v.findViewById(R.id.flipper));
mFlipper.startFlipping();
Spinner s = (Spinner) v.findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String> (getActivity(),
android.R.layout.simple_spinner_item, mStrings);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s.setAdapter(adapter);
s.setOnItemSelectedListener(this);
linear_marcador.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intenttresss = new Intent(getActivity(), Marcador.class);
//intenttresss.putExtra("idioma", idioma);
startActivity(intenttresss);
}
});
imageLoader = new ImageLoader(getActivity());
if ((new UtilsDos(getActivity()).isConnected())){
new DownloadJSONdos().execute();
new DownloadJSON().execute();
}
return v;
}
public void onItemSelected(AdapterView parent, View v, int position, long id) {
switch (position) {
case 0:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
case 1:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
case 2:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
default:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
}
}
public void onNothingSelected(AdapterView parent) {
}
private String[] mStrings = {
"Push up", "Push left", "Cross fade", "Hyperspace"};
private ViewFlipper mFlipper;
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(getActivity());
// Set progressdialog title
//mProgressDialog.setTitle("Android JSON Parse Tutorial");
// Set progressdialog message
mProgressDialog.setMessage("Actualizando...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
elementos_marcador =new ArrayList<String>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions
.getJSONfromURL("myurl");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("results");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
elementos_marcador.add( jsonobject.getString("icono_local"));
elementos_marcador.add( jsonobject.getString("equipo_local"));
elementos_marcador.add( jsonobject.getString("goles_local"));
elementos_marcador.add( jsonobject.getString("icono_visitante"));
elementos_marcador.add( jsonobject.getString("equipo_visitante"));
elementos_marcador.add( jsonobject.getString("goles_visitante"));
elementos_marcador.add( jsonobject.getString("estado"));
elementos_marcador.add( jsonobject.getString("estadio"));
elementos_marcador.add(jsonobject.getString("competicion"));
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
equipo_local.setText(elementos_marcador.get(1));
equipo_visitante.setText(elementos_marcador.get(4));
goles_local.setText(elementos_marcador.get(2));
goles_visitante.setText(elementos_marcador.get(5));
estado.setText(elementos_marcador.get(6));
estadio.setText(elementos_marcador.get(7));
competicion.setText(elementos_marcador.get(8));
imageLoader.DisplayImage(elementos_marcador.get(0), icono_local);
imageLoader.DisplayImage(elementos_marcador.get(3), icono_visitante);
mProgressDialog.dismiss();
}
}
// DownloadJSON AsyncTask
private class DownloadJSONdos extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(getActivity());
// Set progressdialog title
//mProgressDialog.setTitle("Android JSON Parse Tutorial");
// Set progressdialog message
mProgressDialog.setMessage("Actualizando...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
//mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
elementos_proximos =new ArrayList<Proximo_Partido>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions
.getJSONfromURL("myurl");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("results");
for (int i = 0; i < jsonarray.length(); i++) {
Proximo_Partido mi_parti = new Proximo_Partido();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
mi_parti.setCompeticion( jsonobject.getString("competicion"));
mi_parti.setIcono_local( jsonobject.getString("icono_local"));
mi_parti.setIcono_visitante( jsonobject.getString("icono_visitante"));
mi_parti.setHorario( jsonobject.getString("fecha_hora"));
elementos_proximos.add(mi_parti);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
competi_portada_uno.setText(elementos_proximos.get(0).getCompeticion());
competi_portada_dos.setText(elementos_proximos.get(1).getCompeticion());
competi_portada_tres.setText(elementos_proximos.get(2).getCompeticion());
fecha1.setText(elementos_proximos.get(0).getHorario());
fecha2.setText(elementos_proximos.get(1).getHorario());
fecha3.setText(elementos_proximos.get(2).getHorario());
imageLoader.DisplayImage(elementos_proximos.get(0).getIcono_local(), icono_local1);
imageLoader.DisplayImage(elementos_proximos.get(1).getIcono_local(), icono_local2);
imageLoader.DisplayImage(elementos_proximos.get(2).getIcono_local(), icono_local3);
imageLoader.DisplayImage(elementos_proximos.get(0).getIcono_visitante(), icono_visitante1);
imageLoader.DisplayImage(elementos_proximos.get(1).getIcono_visitante(), icono_visitante2);
imageLoader.DisplayImage(elementos_proximos.get(2).getIcono_visitante(), icono_visitante3);
mProgressDialog.dismiss();
}
}
我认为通过网络服务 class 实现 AsynTask 是更好的方法。看看下面我是如何在我的项目中做到这一点的。
代码：
public class WebServiceRestTask extends AsyncTask<HttpUriRequest, Void, Object> {
private static final String TAG = "WebServiceRestTask";
private AbstractHttpClient mClient;
private WeakReference<WebServiceRestCallback> mCallback;
private int ws_task;
public WebServiceRestTask(int ws_task) {
this(new DefaultHttpClient(), ws_task);
}
public WebServiceRestTask(AbstractHttpClient client, int task_number) {
mClient = client;
this.ws_task = task_number;
}
public interface WebServiceRestCallback {
public void onRequestSuccess(String response);
public void onRequestError(Exception error);
}
public void setResponseCallback(WebServiceRestCallback callback) {
mCallback = new WeakReference<WebServiceRestCallback>(callback);
}
@Override
protected Object doInBackground(HttpUriRequest... params) {
try {
HttpUriRequest request = params[0];
HttpResponse serverResponse = mClient.execute(request);
BasicResponseHandler handler = new BasicResponseHandler();
String response = handler.handleResponse(serverResponse);
return response + ws_task;
} catch (Exception e) {
Log.w(TAG, e);
return e;
}
}
@Override
protected void onPostExecute(Object result) {
if (mCallback != null && mCallback.get() != null) {
if (result instanceof String) {
mCallback.get().onRequestSuccess((String) result);
} else if (result instanceof Exception) {
mCallback.get().onRequestError((Exception) result);
} else {
mCallback.get().onRequestError(
new IOException("Unknown Error Contacting Host"));
}
}
}
}
添加
if(jsonobject == null)
return null;
之前
jsonarray = jsonobject.getJSONArray("results");
在doInBackground()方法中AsyncTask
然后在第一个 AsyncTask 的 postExecute() 方法中将其添加到顶部
if(elementos_marcador == null || elementos_marcador.size() == 0)
return;
在第二个 AsyncTask 的 postExecute() 方法中将其添加到顶部
if(elementos_proximos == null || elementos_proximos.size() == 0)
return;
注意： 这会阻止您的应用程序崩溃。但是您仍然必须弄清楚为什么 json 有时会变得腐败。
我正在使用 AsyncTask 从我的服务器 url 中拯救 json 数据。我不知道为什么，但有时运行良好，而其他应用程序则以错误结束。这是我的日志猫的错误：
01-30 22:28:00.998: E/AndroidRuntime(3404): FATAL EXCEPTION: AsyncTask #2
01-30 22:28:00.998: E/AndroidRuntime(3404): Process: my.package.com, PID: 3404
01-30 22:28:00.998: E/AndroidRuntime(3404): java.lang.RuntimeException: An error occured while executing doInBackground()
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask.done(AsyncTask.java:300)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.finishCompletion(FutureTask.java:355)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.setException(FutureTask.java:222)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.run(FutureTask.java:242)
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask$SerialExecutor.run(AsyncTask.java:231)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1112)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:587)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.lang.Thread.run(Thread.java:841)
01-30 22:28:00.998: E/AndroidRuntime(3404): Caused by: java.lang.NullPointerException
01-30 22:28:00.998: E/AndroidRuntime(3404): at my.package.com.ProgramacionActivity$DownloadJSONdos.doInBackground(ProgramacionActivity.java:342)
01-30 22:28:00.998: E/AndroidRuntime(3404): at my.package.com.ProgramacionActivity$DownloadJSONdos.doInBackground(ProgramacionActivity.java:1)
01-30 22:28:00.998: E/AndroidRuntime(3404): at android.os.AsyncTask.call(AsyncTask.java:288)
01-30 22:28:00.998: E/AndroidRuntime(3404): at java.util.concurrent.FutureTask.run(FutureTask.java:237)
01-30 22:28:00.998: E/AndroidRuntime(3404): ... 4 more
01-30 22:28:01.188: E/log_tag(3404): Error parsing data org.json.JSONException: End of input at character 0 of
有人能告诉我为什么这些应用程序有时运行良好而有时运行不佳吗？在我的 activity 中，我有两个这样调用的 AsyncTask：
new DownloadJSONdos().execute();
new DownloadJSON().execute();
我的 activity 代码：
public class ProgramacionActivity extends Fragment implements
AdapterView.OnItemSelectedListener{
ProgressDialog mProgressDialog;
private ViewPager mViewPager;
String idioma;
LinearLayout linear_marcador;
String results;
String jsonStr;
JSONObject jsonobject;
JSONArray jsonarray;
ListView listview;
LazyAdapterHorariosLiga adapter;
ArrayList<HashMap<String, String>> arraylist;
ArrayList<String> elementos_marcador;
ArrayList<Proximo_Partido> elementos_proximos;
JSONArray eventos = null;
// Hashmap for ListView
ArrayList<HashMap<String, String>> eventosList;
ImageLoader imageLoader;
static final String TAG_ICONO_LOCAL= "icono_local";
static final String TAG_EQUIPO_LOCAL= "equipo_local";
static final String TAG_GOLES_LOCAL= "goles_local";
static final String TAG_ICONO_VISITANTE= "icono_visitante";
static final String TAG_EQUIPO_VISITANTE= "equipo_visitante";
static final String TAG_GOLES_VISITANTE= "goles_visitante";
static final String TAG_ESTADO= "estado";
static final String TAG_ESTADIO= "estadio";
static final String TAG_COMPETICION= "competicion";
TextView equipo_local, equipo_visitante, goles_local, goles_visitante, estado, estadio, competicion;
int i;
TextView competi_portada_uno, competi_portada_dos, competi_portada_tres, fecha1, fecha2, fecha3;
ImageView icono_local1, icono_local2, icono_local3,icono_visitante1, icono_visitante2, icono_visitante3;
ImageView icono_local, icono_visitante;
@Override
public View onCreateView(LayoutInflater inflater, ViewGroup container,
Bundle savedInstanceState) {
View v= inflater.inflate(R.layout.programacion_main, container, false);
linear_marcador = (LinearLayout) v.findViewById(R.id.linear_marcador);
animate(linear_marcador).alpha(0).setDuration(0);
mViewPager = (ViewPager) v.findViewById(R.id.viewpager);
PagerTabStrip pagerTabStrip = (PagerTabStrip) v.findViewById(R.id.pagerTabStrip);
pagerTabStrip.setTabIndicatorColor(getResources().getColor(R.color.blanco));
equipo_local=(TextView) v.findViewById(R.id.eq_local);
equipo_visitante=(TextView) v.findViewById(R.id.eq_visitante);
goles_local=(TextView) v.findViewById(R.id.gol_local);
equipo_visitante=(TextView) v.findViewById(R.id.eq_visitante);
goles_visitante=(TextView) v.findViewById(R.id.gol_visitante);
estado=(TextView) v.findViewById(R.id.estado_parti);
estadio=(TextView) v.findViewById(R.id.estadiaco);
competicion=(TextView) v.findViewById(R.id.competicionaca);
icono_local=(ImageView) v.findViewById(R.id.icono_local);
icono_visitante=(ImageView) v.findViewById(R.id.icono_visitante);
icono_local1=(ImageView) v.findViewById(R.id.icono_local1);
icono_visitante1=(ImageView) v.findViewById(R.id.icono_visitante1);
icono_local2=(ImageView) v.findViewById(R.id.icono_local2);
icono_visitante2=(ImageView) v.findViewById(R.id.icono_visitante2);
icono_local3=(ImageView) v.findViewById(R.id.icono_local3);
icono_visitante3=(ImageView) v.findViewById(R.id.icono_visitante3);
competi_portada_uno=(TextView) v.findViewById(R.id.competi_portada1);
competi_portada_dos=(TextView) v.findViewById(R.id.competi_portada2);
competi_portada_tres=(TextView) v.findViewById(R.id.competi_portada3);
fecha1=(TextView) v.findViewById(R.id.fecha1);
fecha2=(TextView) v.findViewById(R.id.fecha2);
fecha3=(TextView) v.findViewById(R.id.fecha3);
Typeface font = Typeface.createFromAsset(getActivity().getAssets(),"fonts/Roboto-Thin.ttf");
Typeface font_dos = Typeface.createFromAsset(getActivity().getAssets(), "fonts/Roboto-Medium.ttf");
equipo_local.setTypeface(font_dos);
equipo_visitante.setTypeface(font_dos);
estadio.setTypeface(font_dos);
competicion.setTypeface(font_dos);
goles_local.setTypeface(font);
goles_visitante.setTypeface(font);
competi_portada_uno.setTypeface(font_dos);
competi_portada_dos.setTypeface(font_dos);
competi_portada_tres.setTypeface(font_dos);
fecha1.setTypeface(font_dos);
fecha2.setTypeface(font_dos);
fecha3.setTypeface(font_dos);
new java.util.Timer().schedule(
new java.util.TimerTask() {
@Override
public void run() {
animate(linear_marcador).alpha(1).setDuration(1200);
}
},
2500
);
TitleAdapter titleAdapter = new TitleAdapter(getActivity().getSupportFragmentManager());
mViewPager.setAdapter(titleAdapter);
mViewPager.setCurrentItem(0);
mFlipper = ((ViewFlipper) v.findViewById(R.id.flipper));
mFlipper.startFlipping();
Spinner s = (Spinner) v.findViewById(R.id.spinner);
ArrayAdapter<String> adapter = new ArrayAdapter<String> (getActivity(),
android.R.layout.simple_spinner_item, mStrings);
adapter.setDropDownViewResource(android.R.layout.simple_spinner_dropdown_item);
s.setAdapter(adapter);
s.setOnItemSelectedListener(this);
linear_marcador.setOnClickListener(new View.OnClickListener() {
@Override
public void onClick(View v) {
Intent intenttresss = new Intent(getActivity(), Marcador.class);
//intenttresss.putExtra("idioma", idioma);
startActivity(intenttresss);
}
});
imageLoader = new ImageLoader(getActivity());
if ((new UtilsDos(getActivity()).isConnected())){
new DownloadJSONdos().execute();
new DownloadJSON().execute();
}
return v;
}
public void onItemSelected(AdapterView parent, View v, int position, long id) {
switch (position) {
case 0:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
case 1:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
case 2:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
default:
mFlipper.setInAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_in));
mFlipper.setOutAnimation(AnimationUtils.loadAnimation(getActivity(),
android.R.anim.fade_out));
break;
}
}
public void onNothingSelected(AdapterView parent) {
}
private String[] mStrings = {
"Push up", "Push left", "Cross fade", "Hyperspace"};
private ViewFlipper mFlipper;
// DownloadJSON AsyncTask
private class DownloadJSON extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(getActivity());
// Set progressdialog title
//mProgressDialog.setTitle("Android JSON Parse Tutorial");
// Set progressdialog message
mProgressDialog.setMessage("Actualizando...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
elementos_marcador =new ArrayList<String>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions
.getJSONfromURL("myurl");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("results");
for (int i = 0; i < jsonarray.length(); i++) {
HashMap<String, String> map = new HashMap<String, String>();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
elementos_marcador.add( jsonobject.getString("icono_local"));
elementos_marcador.add( jsonobject.getString("equipo_local"));
elementos_marcador.add( jsonobject.getString("goles_local"));
elementos_marcador.add( jsonobject.getString("icono_visitante"));
elementos_marcador.add( jsonobject.getString("equipo_visitante"));
elementos_marcador.add( jsonobject.getString("goles_visitante"));
elementos_marcador.add( jsonobject.getString("estado"));
elementos_marcador.add( jsonobject.getString("estadio"));
elementos_marcador.add(jsonobject.getString("competicion"));
arraylist.add(map);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
// Locate the listview in listview_main.xml
equipo_local.setText(elementos_marcador.get(1));
equipo_visitante.setText(elementos_marcador.get(4));
goles_local.setText(elementos_marcador.get(2));
goles_visitante.setText(elementos_marcador.get(5));
estado.setText(elementos_marcador.get(6));
estadio.setText(elementos_marcador.get(7));
competicion.setText(elementos_marcador.get(8));
imageLoader.DisplayImage(elementos_marcador.get(0), icono_local);
imageLoader.DisplayImage(elementos_marcador.get(3), icono_visitante);
mProgressDialog.dismiss();
}
}
// DownloadJSON AsyncTask
private class DownloadJSONdos extends AsyncTask<Void, Void, Void> {
@Override
protected void onPreExecute() {
super.onPreExecute();
// Create a progressdialog
mProgressDialog = new ProgressDialog(getActivity());
// Set progressdialog title
//mProgressDialog.setTitle("Android JSON Parse Tutorial");
// Set progressdialog message
mProgressDialog.setMessage("Actualizando...");
mProgressDialog.setIndeterminate(false);
// Show progressdialog
//mProgressDialog.show();
}
@Override
protected Void doInBackground(Void... params) {
// Create an array
arraylist = new ArrayList<HashMap<String, String>>();
elementos_proximos =new ArrayList<Proximo_Partido>();
// Retrieve JSON Objects from the given URL address
jsonobject = JSONfunctions
.getJSONfromURL("myurl");
try {
// Locate the array name in JSON
jsonarray = jsonobject.getJSONArray("results");
for (int i = 0; i < jsonarray.length(); i++) {
Proximo_Partido mi_parti = new Proximo_Partido();
jsonobject = jsonarray.getJSONObject(i);
// Retrive JSON Objects
mi_parti.setCompeticion( jsonobject.getString("competicion"));
mi_parti.setIcono_local( jsonobject.getString("icono_local"));
mi_parti.setIcono_visitante( jsonobject.getString("icono_visitante"));
mi_parti.setHorario( jsonobject.getString("fecha_hora"));
elementos_proximos.add(mi_parti);
}
} catch (JSONException e) {
Log.e("Error", e.getMessage());
e.printStackTrace();
}
return null;
}
@Override
protected void onPostExecute(Void args) {
competi_portada_uno.setText(elementos_proximos.get(0).getCompeticion());
competi_portada_dos.setText(elementos_proximos.get(1).getCompeticion());
competi_portada_tres.setText(elementos_proximos.get(2).getCompeticion());
fecha1.setText(elementos_proximos.get(0).getHorario());
fecha2.setText(elementos_proximos.get(1).getHorario());
fecha3.setText(elementos_proximos.get(2).getHorario());
imageLoader.DisplayImage(elementos_proximos.get(0).getIcono_local(), icono_local1);
imageLoader.DisplayImage(elementos_proximos.get(1).getIcono_local(), icono_local2);
imageLoader.DisplayImage(elementos_proximos.get(2).getIcono_local(), icono_local3);
imageLoader.DisplayImage(elementos_proximos.get(0).getIcono_visitante(), icono_visitante1);
imageLoader.DisplayImage(elementos_proximos.get(1).getIcono_visitante(), icono_visitante2);
imageLoader.DisplayImage(elementos_proximos.get(2).getIcono_visitante(), icono_visitante3);
mProgressDialog.dismiss();
}
}
我认为通过网络服务 class 实现 AsynTask 是更好的方法。看看下面我是如何在我的项目中做到这一点的。
代码：
public class WebServiceRestTask extends AsyncTask<HttpUriRequest, Void, Object> {
private static final String TAG = "WebServiceRestTask";
private AbstractHttpClient mClient;
private WeakReference<WebServiceRestCallback> mCallback;
private int ws_task;
public WebServiceRestTask(int ws_task) {
this(new DefaultHttpClient(), ws_task);
}
public WebServiceRestTask(AbstractHttpClient client, int task_number) {
mClient = client;
this.ws_task = task_number;
}
public interface WebServiceRestCallback {
public void onRequestSuccess(String response);
public void onRequestError(Exception error);
}
public void setResponseCallback(WebServiceRestCallback callback) {
mCallback = new WeakReference<WebServiceRestCallback>(callback);
}
@Override
protected Object doInBackground(HttpUriRequest... params) {
try {
HttpUriRequest request = params[0];
HttpResponse serverResponse = mClient.execute(request);
BasicResponseHandler handler = new BasicResponseHandler();
String response = handler.handleResponse(serverResponse);
return response + ws_task;
} catch (Exception e) {
Log.w(TAG, e);
return e;
}
}
@Override
protected void onPostExecute(Object result) {
if (mCallback != null && mCallback.get() != null) {
if (result instanceof String) {
mCallback.get().onRequestSuccess((String) result);
} else if (result instanceof Exception) {
mCallback.get().onRequestError((Exception) result);
} else {
mCallback.get().onRequestError(
new IOException("Unknown Error Contacting Host"));
}
}
}
}
添加
if(jsonobject == null)
return null;
之前
jsonarray = jsonobject.getJSONArray("results");
在doInBackground()方法中AsyncTask
然后在第一个 AsyncTask 的 postExecute() 方法中将其添加到顶部
if(elementos_marcador == null || elementos_marcador.size() == 0)
return;
在第二个 AsyncTask 的 postExecute() 方法中将其添加到顶部
if(elementos_proximos == null || elementos_proximos.size() == 0)
return;
注意： 这会阻止您的应用程序崩溃。但是您仍然必须弄清楚为什么 json 有时会变得腐败。