Android GCM：檢索設備註冊標識

Question

我正在嘗試使用Implementing GCM Client獲取GCM設備註冊標識。我使用了一個類Functions來實現這個過程。這裏是我的

public class Functions { 


public Functions(Activity activity) { 
    // TODO Auto-generated constructor stub 
    this.activity = activity; 
    this.prefs = activity.getSharedPreferences(activity.getClass().getSimpleName(), Context.MODE_PRIVATE); 
} 

public void deviceRegistrationID(){ 
    if (checkPlayServices()) { 
     gcm = GoogleCloudMessaging.getInstance(activity); 
     regid = getRegistrationId(activity); 

     if (regid.isEmpty()) { 
      registerInBackground(); 
     } 

    } else { 
     Log.i(TAG, "No valid Google Play Services APK found."); 
    } 

} 

public String getGCMRegistrationID(){ 
    String registeredID = prefs.getString(PROPERTY_REG_ID, ""); 
    System.out.println("The REG ID:"+prefs.getString(PROPERTY_REG_ID, "")); 
    return registeredID; 
} 

private boolean checkPlayServices() { 
    int resultCode = GooglePlayServicesUtil 
      .isGooglePlayServicesAvailable(activity); 
    if (resultCode != ConnectionResult.SUCCESS) { 
     if (GooglePlayServicesUtil.isUserRecoverableError(resultCode)) { 
      GooglePlayServicesUtil.getErrorDialog(resultCode, activity, 
        PLAY_SERVICES_RESOLUTION_REQUEST).show(); 
     } else { 
      activity.finish(); 
     } 
     return false; 
    } 
    return true; 
} 

private String getRegistrationId(Context context) { 
    String registrationId = prefs.getString(PROPERTY_REG_ID, ""); 
    if (registrationId.isEmpty()) { 
     Log.i(TAG, "Registration not found."); 
     return ""; 
    } 
    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; 
} 

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); 
    } 
} 

private void registerInBackground() { 
    new AsyncTask<Void, Void, String>() { 
     @Override 
     protected String doInBackground(Void... params) { 
      String msg = ""; 
      try { 
       if (gcm == null) { 
        gcm = GoogleCloudMessaging.getInstance(activity); 
       } 
       regid = gcm.register(SENDER_ID); 
       msg = "Device registered, registration ID=" + regid; 
       storeRegistrationId(activity, regid); 
      } catch (IOException ex) { 
       msg = "Error :" + ex.getMessage(); 
      } 
      return msg; 
     } 

     @Override 
     protected void onPostExecute(String msg) { 
      Toast.makeText(activity, msg, Toast.LENGTH_LONG).show(); 
     } 
    }.execute(null, null, null); 
} 

private void storeRegistrationId(Context context, String regId) { 
    int appVersion = getAppVersion(context); 
    Editor editor = prefs.edit(); 
    editor.putString(PROPERTY_REG_ID, regId); 
    editor.putInt(PROPERTY_APP_VERSION, appVersion); 
    editor.commit(); 
}} 

類在我MainActivity我試圖獲得註冊ID以下列方式

@Override 
protected void onCreate(Bundle savedInstanceState) { 
    super.onCreate(savedInstanceState); 
    functions = new Functions(MainActivity.this); 
    functions.deviceRegistrationID(); 
    registrationId = functions.getGCMRegistrationID();} 

這裏registrationId產生null值。但在Functions類方法

private void registerInBackground() { 
    new AsyncTask<Void, Void, String>() { 
     @Override 
     protected String doInBackground(Void... params) { 
      ....... 
     } 

     @Override 
     protected void onPostExecute(String msg) { 
      Toast.makeText(activity, msg, Toast.LENGTH_LONG).show(); 
     } 
    }.execute(null, null, null); 
} 

它示出了在Toast和註冊ID

public String getGCMRegistrationID(){ 
    String registeredID = prefs.getString(PROPERTY_REG_ID, ""); 
    System.out.println("The REG ID:"+prefs.getString(PROPERTY_REG_ID, "")); 
    return registeredID; 
} 

它示出了在LogCatempty註冊ID。 我如何獲得註冊ID？

Answer 1

這行代碼可以幫助你的提問

private String getRegistrationId(Context context) { 

final SharedPreferences prefs = getGCMPreferences(context); 

String registrationId = prefs.getString(PROPERTY_REG_ID, ""); 

if (registrationId.length() == 0) { 

    Log.v(TAG, "Registration not found."); 

    return ""; 

} 

// check if app was updated; if so, it must clear registration id to 

// avoid a race condition if GCM sends a message 

int registeredVersion = prefs.getInt(PROPERTY_APP_VERSION, Integer.MIN_VALUE); 

int currentVersion = getAppVersion(context); 

    if (registeredVersion != currentVersion || isRegistrationExpired()) { 

Log.v(TAG, "App version changed or registration expired."); 

return ""; 



return registrationId; 

} 

或作爲一個參考，你可以檢查此鏈接 Handling registration ID changes in Google Cloud Messaging on Android