altbeacon - 无法联系服务来设置扫描周期

Question

我使用android-beacon-library (altbeacon)来检测周围，前景和背景的信标。我使用了Samples中显示的示例。我成功地让它检测到我的一个灯塔，但它并不真正工作。有时它会检测并打开新的活动，有时它不会。

不知道这是我的编码错误还是别的。至于我的理解，通过在Application类中实现BeaconManager初始化，它会在应用程序打开后自动扫描信标。所以，我没有在我的Activity类中初始化任何东西，我只是让它扫描应用程序级别。

我已经通过BeaconManager指定我的灯塔在应用程序类，如下所示：

public class BeaconReferenceApplication extends Application implements BootstrapNotifier, RangeNotifier { 
    @Override 
    public void onCreate() { 
     super.onCreate(); 
     Log.d(TAG, "App started up"); 

     BeaconManager beaconManager = BeaconManager.getInstanceForApplication(this); 
     BeaconManager.setDebug(true); 

     beaconManager.getBeaconParsers().add(new BeaconParser(). 
       setBeaconLayout("m:2-3=0215,i:4-19,i:20-21,i:22-23,p:24-24")); 

     beaconManager.setBackgroundScanPeriod(1100l); 

     beaconManager.setBackgroundBetweenScanPeriod(600000l); 
     beaconManager.setRangeNotifier(this); 

     // Constants is a class containing one of my beacon UUID, major and minor 
     Region region = new Region("com.bledemo.com.boostrapRegion", Identifier.parse(Constants.BT_UUID), 
       Identifier.fromInt(Constants.BT_MAJOR), Identifier.fromInt(Constants.BT_MINOR)); 

     regionBootstrap = new RegionBootstrap(this, region); 

     backgroundPowerSaver = new BackgroundPowerSaver(this); 

     mInstance = this; // Volley networking instance 
    } 

    // fires up Activity once a specified beacon is detected 
    @Override 
    public void didEnterRegion(Region region) { 
     Log.d(TAG, "Got a didEnterRegion call"); 

     regionBootstrap.disable(); 

     Intent intent = new Intent(this, MainActivity.class); 
     intent.putExtra("uuid", region.getId1().toString()); 
     intent.putExtra("major", region.getId2().toString()); 
     intent.putExtra("minor", region.getId3().toString()); 
     intent.setFlags(Intent.FLAG_ACTIVITY_NEW_TASK); 
     this.startActivity(intent); 
    } 

} 

在MainActivity，

public class MainActivity extends Activity { 



    @Override 
    protected void onCreate(Bundle savedInstanceState) { 
     super.onCreate(savedInstanceState); 
     setContentView(R.layout.activity_main); 

     // get intent extras, etc 

     if (savedInstanceState == null) { 
      getFragmentManager().beginTransaction() 
        .add(R.id.container, fragment) 
        .commit(); 
     } 
    } 

    /** 
    * A placeholder fragment containing a simple view. 
    */ 
    public static class PlaceholderFragment extends Fragment { 

     private static final String TAG = PlaceholderFragment.class.getSimpleName(); 

     public PlaceholderFragment() { 
     } 

     @Override 
     public View onCreateView(LayoutInflater inflater, ViewGroup container, 
           Bundle savedInstanceState) { 

      View rootView = inflater.inflate(R.layout.fragment_main, container, false); 
      tvRegion = (TextView) rootView.findViewById(R.id.tvRegion); 

      uuid = getArguments().getString("uuid"); 
      major = getArguments().getString("major"); 
      minor = getArguments().getString("minor"); 

      appController = BeaconReferenceApplication.getInstance(); 

      return rootView; 
     } 

     @Override 
     public void onActivityCreated(Bundle savedInstanceState) { 
      super.onActivityCreated(savedInstanceState); 

      DateFormat dateFormat = new SimpleDateFormat("yyyy/MM/dd HH:mm:ss"); 
      Date date = new Date(); 

      if (uuid != null && !uuid.isEmpty()) { 
       Log.d(TAG, "uuid not null"); 

       tvRegion.setText("Beacon found= " + uuid 
           + "\nLast found " + dateFormat.format(date) 
           + "\nSet on 30 mins interval" 
           + "\nRequest to API initiated" 
       ); 

       initBeaconAction(uuid); // init notification 
      } else { 
       tvRegion.setText("Beacon not found" 
           + "\nLast found " + dateFormat.format(date) 
           + "\nSet on 30 mins interval" 
       ); 
      } 
     } 
    } 

} 

清单中，

<uses-permission android:name="android.permission.BLUETOOTH" /> 
<uses-permission android:name="android.permission.BLUETOOTH_ADMIN" /> 
<uses-permission android:name="android.permission.INTERNET"/> 

<application 
    android:name=".BeaconReferenceApplication" 
    android:allowBackup="true" 
    android:icon="@drawable/ic_launcher" 
    android:label="@string/app_name" 
    android:theme="@style/AppTheme" > 
    <activity 
     android:name=".MainActivity" 
     android:label="@string/title_activity_main" 
     android:launchMode="singleInstance" > 
     <intent-filter> 
      <action android:name="android.intent.action.MAIN" /> 
      <category android:name="android.intent.category.LAUNCHER" /> 
     </intent-filter> 
    </activity> 
</application> 

对于错误，这里是我的full logcat debug。正如你所看到的，有很多Cannot contact service to set scan periods。我假设它没有正确设置扫描周期。

当我打开应用程序并在应用程序关闭时还在后台扫描它时，我该如何进行扫描？

Answer 1

代码设置的方式，它只会在第一次看到信标时启动活动。这是因为regionBootstrap.disable();代码行基本上停止了信标检测。

如果你拿出regionBootstrap.disable();这条线，那么它会在每次开始看到与你的区域相匹配的信标时发送一个启动活动的意图。由于清单中标记为singleInstance的活动，如果它已经启动，它将重新启动相同的活动。