我正在开发一个非常简单的应用程序，它接收GCM的推送通知。 SO中有类似的问题，但this is the only one I found尝试更新ListView挂钩中的onNewIntent()，但没有帮助。
“业务逻辑”应该是：
如果在应用程序不在前台时收到通知，请将其添加到ListView（因此，ListView只有一个项目）。
如果在应用程序处于前台时收到通知，请将其添加到ListView（因此，它将包含n> 1项）。
这是Activity的{{1}}：
ListView但是，虽然使用正确的通知调用package ar.edu.uca.ingenieria.notificaciones;
import android.app.Activity;
import android.content.Context;
import android.content.Intent;
import android.content.SharedPreferences;
import android.content.pm.PackageInfo;
import android.content.pm.PackageManager.NameNotFoundException;
import android.content.res.Resources;
import android.os.AsyncTask;
import android.os.Bundle;
import android.util.Log;
import android.widget.ListView;
import android.widget.TextView;
import com.google.android.gms.common.ConnectionResult;
import com.google.android.gms.common.GooglePlayServicesUtil;
import com.google.android.gms.gcm.GoogleCloudMessaging;
import java.io.IOException;
import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import ar.edu.uca.ingenieria.notificaciones.adapter.NotificacionesAdapter;
import ar.edu.uca.ingenieria.notificaciones.gcm.GcmIntentService;
import ar.edu.uca.ingenieria.notificaciones.model.Notificacion;
/**
* Main UI for the demo app.
*/
public class MainActivity extends Activity {
public static final String PROPERTY_REG_ID = "registration_id";
private static final String PROPERTY_APP_VERSION = "appVersion";
private static final int PLAY_SERVICES_RESOLUTION_REQUEST = 9000;
private static final String TAG = "GCM Demo";
/**
* Es el project number obtenido en la API Console, como se explica en "Getting Started."
*/
String senderId;
TextView mDisplay;
List<Notificacion> notificaciones;
private ListView notificacionesListView;
GoogleCloudMessaging gcm;
Context context;
String regid;
private NotificacionesAdapter notificacionesAdapter;
@Override
public void onCreate(Bundle savedInstanceState) {
super.onCreate(savedInstanceState);
setContentView(R.layout.activity_main);
mDisplay = (TextView) findViewById(R.id.display);
context = getApplicationContext();
senderId = getSenderId();
intentarRegistrarGooglePlayServices();
Notificacion notificacion = getNotificacionFromIntent();
this.notificaciones = new ArrayList<Notificacion>();
inicializarListView(notificacion);
}
private void inicializarListView(Notificacion notificacion) {
this.notificaciones.add(notificacion);
// Create the adapter to convert the array to views
notificacionesAdapter = new NotificacionesAdapter(this, this.notificaciones);
// Attach the adapter to a ListView
this.notificacionesListView = (ListView) findViewById(R.id.lista_notificaciones);
this.notificacionesListView.setAdapter(notificacionesAdapter);
}
private void agregarNotificacion(Notificacion notificacion) {
this.notificaciones.add(notificacion);
// this.notificacionesAdapter.add(notificacion);
this.notificacionesAdapter.notifyDataSetChanged();
}
/**
* Verifica si Google Play Services está instalado en el dispositivo. De ser así, intenta
* registrarse y guarda el regid obtenido.
*/
private void intentarRegistrarGooglePlayServices() {
// Check device for Play Services APK. If check succeeds, proceed with GCM registration.
if (checkPlayServices()) {
gcm = GoogleCloudMessaging.getInstance(this);
regid = getRegistrationId(context);
if (regid.isEmpty()) {
registerInBackground();
}
} else {
Log.i(TAG, "No valid Google Play Services APK found.");
}
Log.i(TAG, "regid: " + this.regid);
}
private Notificacion getNotificacionFromIntent() {
String tituloNotificacion = (String) getIntent().getCharSequenceExtra(GcmIntentService.GCM_TITULO);
Log.d(TAG, "Título: " + tituloNotificacion);
String mensajeNotificacion = (String) getIntent().getCharSequenceExtra(GcmIntentService.GCM_MENSAJE);
Log.d(TAG, "Mensaje: " + mensajeNotificacion);
// TODO esto muestra "1/1/1970" si no viene la fecha...
long fechaMilisegundos = getIntent().getLongExtra(GcmIntentService.GCM_FECHA, new Date(0).getTime());
Date fechaNotificacion = new Date(fechaMilisegundos);
return new Notificacion(tituloNotificacion, mensajeNotificacion, fechaNotificacion);
}
@Override
protected void onResume() {
super.onResume();
// Check device for Play Services APK.
checkPlayServices();
Log.i(TAG, "regid: " + this.regid);
Log.d(TAG, "onResume");
}
@Override
protected void onNewIntent(Intent intent) {
super.onNewIntent(intent);
Log.d(TAG, "onNewIntent");
this.setIntent(intent);
this.agregarNotificacion(this.getNotificacionFromIntent());
}
/**
* Check the device to make sure it has the Google Play Services APK. If
* it doesn't, display a dialog that allows users to download the APK from
* the Google Play Store or enable it in the device's system settings.
*/
private boolean checkPlayServices() {
int resultCode = GooglePlayServicesUtil.isGooglePlayServicesAvailable(this);
if (resultCode != ConnectionResult.SUCCESS) {
if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) {
GooglePlayServicesUtil.getErrorDialog(resultCode, this,
PLAY_SERVICES_RESOLUTION_REQUEST).show();
} else {
Log.i(TAG, "This device is not supported.");
finish();
}
return false;
}
return true;
}
/**
* Stores the registration ID and the app versionCode in the application's
* {@code SharedPreferences}.
*
* @param context application's context.
* @param regId registration ID
*/
private void storeRegistrationId(Context context, String regId) {
final SharedPreferences prefs = getGcmPreferences(context);
int appVersion = getAppVersion(context);
Log.i(TAG, "Saving regId on app version " + appVersion);
SharedPreferences.Editor editor = prefs.edit();
editor.putString(PROPERTY_REG_ID, regId);
editor.putInt(PROPERTY_APP_VERSION, appVersion);
editor.apply();
}
/**
* Gets the current registration ID for application on GCM service, if there is one.
* <p>
* If result is empty, the app needs to register.
*
* @return registration ID, or empty string if there is no existing
* registration ID.
*/
private String getRegistrationId(Context context) {
final SharedPreferences prefs = getGcmPreferences(context);
String registrationId = prefs.getString(PROPERTY_REG_ID, "");
if (registrationId.isEmpty()) {
Log.i(TAG, "Registration not found.");
return "";
}
// Check if app was updated; if so, it must clear the registration ID
// since the existing regID is not guaranteed to work with the new
// app version.
int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE);
int currentVersion = getAppVersion(context);
if (registeredVersion != currentVersion) {
Log.i(TAG, "App version changed.");
return "";
}
return registrationId;
}
/**
* Registers the application with GCM servers asynchronously.
* <p>
* Stores the registration ID and the app versionCode in the application's
* shared preferences.
*/
private void registerInBackground() {
new AsyncTask<Void, Void, String>() {
@Override
protected String doInBackground(Void... params) {
String msg = "";
try {
if (gcm == null) {
gcm = GoogleCloudMessaging.getInstance(context);
}
regid = gcm.register(senderId);
msg = "Device registered, registration ID=" + regid;
// You should send the registration ID to your server over HTTP, so it
// can use GCM/HTTP or CCS to send messages to your app.
sendRegistrationIdToBackend();
// For this demo: we don't need to send it because the device will send
// upstream messages to a server that echo back the message using the
// 'from' address in the message.
// Persist the regID - no need to register again.
storeRegistrationId(context, regid);
} catch (IOException ex) {
msg = "Error :" + ex.getMessage();
// If there is an error, don't just keep trying to register.
// Require the user to click a button again, or perform
// exponential back-off.
}
return msg;
}
@Override
protected void onPostExecute(String msg) {
mDisplay.append(msg + "\n");
}
}.execute(null, null, null);
}
@Override
protected void onDestroy() {
super.onDestroy();
}
/**
* @return Application's version code from the {@code PackageManager}.
*/
private static int getAppVersion(Context context) {
try {
PackageInfo packageInfo = context.getPackageManager()
.getPackageInfo(context.getPackageName(), 0);
return packageInfo.versionCode;
} catch (NameNotFoundException e) {
// should never happen
throw new RuntimeException("Could not get package name: " + e);
}
}
/**
* @return Application's {@code SharedPreferences}.
*/
private SharedPreferences getGcmPreferences(Context context) {
// This sample app persists the registration ID in shared preferences, but
// how you store the regID in your app is up to you.
return getSharedPreferences(MainActivity.class.getSimpleName(),
Context.MODE_PRIVATE);
}
// TODO implementar esto del lado del server
/**
* Sends the registration ID to your server over HTTP, so it can use GCM/HTTP or CCS to send
* messages to your app. Not needed for this demo since the device sends upstream messages
* to a server that echoes back the message using the 'from' address in the message.
*/
private void sendRegistrationIdToBackend() {
// Your implementation here.
}
// TODO: esto no es responsabilidad de esta clase...
// Tal vez un "setting provider" o similar
private String getSenderId() {
Resources res = getResources();
return res.getString(R.string.senderId);
}
}
方法，但它不会更新ListView项。
我做了很多谷歌搜索，并读取应该使用像agregarNotificacion()这样的方法，但它也不起作用（这就是我留下评论的原因）。
因此，在这种特殊情况下（在一个Activity钩子中创建ListView，并在另一个钩子中更新它），我怎么能刷新ListView？
最后两个考虑因素：
myAdapter.add()方法返回一个具有空字段的对象，而不是null getNotificacionFromIntent()）。我知道它，但运行和退出应用程序是一种快速的解决方法。任何帮助或指示都将受到高度赞赏。 问候。
答案 0 :(得分：0)
解决方案是从ListActivity延伸，然后通过this.notificacionesAdapter.add(newItem)发送新项目。