android - PendingIntents 保持缓存相同的对象

Question

我在尝试通过 Intent 和未决 Intent 将数据传递给 BroadcastReceiver 时遇到了一些问题，涉及接近警报。更具体地说，我试图传递一个对象，其中包括用户不断变化的位置。我已经尝试了这里(不仅如此)提出的各种策略，但都没有奏效，当在 BroadcastReceiver 端检索 Intent 时，会导致空值或与首次创建的 Intent 相同。使用的策略:

• 标记携带对象的 Intent :FLAG_ACTIVITY_NEW_TASK+FLAG_ACTIVITY_CLEAR_TOP+FLAG_ACTIVITY_SINGLE_TOP结果:BroadacastReceiver 端的空值
• 标记使用初始 Intent 创建的待定 Intent ，带有:FLAG_UPDATE_CURRENT 或 FLAG_CANCEL_CURRENT结果:BroadacastReceiver 端的空值
• 使用 System.currentTimeMillis() 获取 Intent 或未决 Intent 的随机 ID；结果:根本没有触发或接收 Intent
• 上面没有描述。结果:每次取回相同的初始值。

调用方法的代码(从任何实验中剥离/产生空值):

private void setProximityAlert(MyCar myCar) { 
  String locService = Context.LOCATION_SERVICE; 
  LocationManager locationManager; 
  locationManager = (LocationManager)getSystemService(locService);
  float radius = myCar.getMyCarRadius(); 
  long expiration = myCar.getMyCarExpiration(); 
  myService.setMyDriverLat(userLat);//setting user's position
  myService.setMyDriverLng(userLng);//setting user's position
  Intent  intent = new Intent(myCar.getMyCarName());
  intent.putExtra("myCar",myCar);

  PendingIntent proximityIntent = PendingIntent.getBroadcast(this, -1, intent, 0);
  locationManager.addProximityAlert(myCar.getMyCarLat(), myCar.getMyCarLng(), radius, expiration, proximityIntent);
 }

设置intent过滤器和注册BroadcastReceiver的调用方法代码:

public void addNewCarPoint (MyCar myCar){
        IntentFilter filter = new IntentFilter(myCar.getMyCarName());
        registerReceiver(new ProximityAlertReceiver(), filter);
        setProximityAlert(myCar);
    }

BroadcastReceiver 端的代码:

public class ProximityAlertReceiver extends BroadcastReceiver {
 @Override
 public void onReceive (Context context, Intent intent) {
 MyCar myCar=(MyCar)intent.getParcelableExtra("myCar");
  driverLoc=(String)Double.toString(myCar.getMyDriverLat());
  Toast.makeText(context, userLoc, Toast.LENGTH_SHORT).show();
  Intent i = new Intent(context, MyCarDiscoveryPrompt.class);
  context.startActivity(i);//firing intent
 }
 public void intentDataLoader(){      
 }

任何想法都非常受欢迎。提前谢谢你。

Answer 1

嗯，我想我找到了一些东西:

我将用于检测接近警报的 BroadcastReceiver (ProximityAlerReceiver) 放置在 LocationListener.class 所在的同一个类 (MyCarTracking.class) 中。这个，提供对新位置更新的即时访问，创建一个包裹在新 pendingIntent 中的新 Intent ，以触发 BroadcastReceiver(仅当满足邻近条件时)。flags:FLAG_ACTIVITY_NEW_TASK+FLAG_ACTIVITY_SINGLE_TOP 和 FLAG_CANCEL_CURRENT on intent 和 pendingIntent 分别保留。更具体地说:

LocationListener 代码:

private final LocationListener locationListener = new LocationListener() { 
        public void onLocationChanged(Location location) {
            updateWithNewLocation(location);//update application based on new location
        }
        public void onProviderDisabled(String provider){ 
            updateWithNewLocation(null);//update application if provider disabled
        }
        public void onProviderEnabled(String provider){
            // Update application if provider enabled
        } 
        public void onStatusChanged(String provider, int status, Bundle extras){ 
            //update application if provider hardware status changed
        }
    };

setProximityAlert() 方法的代码:

private void setProximityAlert() { 
    String locService = Context.LOCATION_SERVICE; 
    Context context =getApplicationContext();
    LocationManager locationManager; 
    locationManager = (LocationManager)getSystemService(locService);
    float radius = myCar.getMyCarRadius(); 
    long expiration = myCar.getMyCarExpiration(); 
    Intent  intent = new Intent(CAR_DISCOVERED);
    intent.putExtra("myCar",myCar);
    locationManager.getLastKnownLocation(provider);
    intent.addFlags(Intent.FLAG_ACTIVITY_NEW_TASK).addFlags(Intent.FLAG_ACTIVITY_SINGLE_TOP);//flagging intent
    PendingIntent proximityIntent = PendingIntent.getBroadcast(context, -1, intent, PendingIntent.FLAG_CANCEL_CURRENT);//flagging pendingIntent         
    locationManager.addProximityAlert(myCar.getMyCarLat(), myCar.getMyCarLng(), radius, expiration, proximityIntent);//setting proximity alert
}

此解决方案可通过新的位置更新产生新的 Intent 。谢谢大家的帮助和兴趣:)