向 requestLocationUpdates intentService 发送额外信息会中断位置更新

Question

我无法使用我的PendingIntent 发送额外的字符串，我将其传递给LocationServices.FusedLocationApi.requestLocationUpdates(GoogleApiClient client, LocationRequest request, PendingIntent callbackIntent)。

我在Intent 上添加的用户名似乎正在破坏requestLocationUpdates 试图移交给我的IntentService 的位置，因为intent.getParcelableExtra(FusedLocationProviderApi.KEY_LOCATION_CHANGED) 返回null。

编辑

我尝试创建一个实现Parcelable 的User 类并将其作为额外的：

mRequestLocationUpdatesIntent.putExtra("username", new User(username));

我还尝试将Parcelable User 放入Bundle 中，正如此错误报告https://code.google.com/p/android/issues/detail?id=81812 中的评论所建议的那样：

Bundle userBundle = new Bundle();
userBundle.putParcelable("user", new User(username));
mRequestLocationUpdatesIntent.putExtra("user", userBundle);

为我服务：

Bundle userBundle = intent.getBundleExtra("user");
User user = userBundle.getParcelable("user");
String username = user.getUsername();

但是，这些方法都没有任何区别。每当我在意图中添加任何额外内容时，更新发生时该位置永远不会添加到意图中。

我设置了这个IntentService 来处理位置更新：

public class LocationUpdateService extends IntentService {

    private final String TAG = "LocationUpdateService";

    public LocationUpdateService() {
        super("LocationUpdateService");
    }


    @Override
    protected void onHandleIntent(Intent intent) {

        Log.d(TAG, "onHandleIntent");

        Bundle extras = intent.getExtras();
        Log.d(TAG, "keys found inside intent: " + TextUtils.join(", ", extras.keySet()));

        String username = intent.getStringExtra("username");

        if (username != null) {
            Log.d(TAG, "username: " + username);
        } else {
            Log.d(TAG, "username: null");
        }

        if (!intent.hasExtra(FusedLocationProviderApi.KEY_LOCATION_CHANGED)) {
            Log.d(TAG, "intent does not have location :(");
        }

        Location location = intent.getParcelableExtra(FusedLocationProviderApi.KEY_LOCATION_CHANGED);

        if (location == null) {
            Log.d(TAG, "location == null :(");
        }

        Log.d(TAG, "latitude " + String.valueOf(location.getLatitude()));
        Log.d(TAG, "longitude " + String.valueOf(location.getLongitude()));

        ...

    }


}

当用户点击一个按钮时，startLocationUpdates 在我的主要活动中被调用：

主要活动类：

...

Boolean mLocationUpdatesEnabled = false;

protected void createLocationRequest() {
    mLocationRequest = new LocationRequest();
    mLocationRequest.setInterval(LOCATION_UPDATE_INTERVAL);
    mLocationRequest.setFastestInterval(LOCATION_UPDATE_FASTEST_INTERVAL);
    mLocationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
}

protected void startLocationUpdates() {

    Log.d(TAG, "startng location updates...");

    mLocationUpdatesEnabled = true;

    if (mLocationRequest == null) {
        createLocationRequest();
    }

    // create the Intent to use WebViewActivity to handle results
    Intent mRequestLocationUpdatesIntent = new Intent(this, LocationUpdateService.class);

    // create a PendingIntent
    mRequestLocationUpdatesPendingIntent = PendingIntent.getService(getApplicationContext(), 0,
            mRequestLocationUpdatesIntent,
            PendingIntent.FLAG_CANCEL_CURRENT);

    // request location updates
    LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient,
            mLocationRequest,
            mRequestLocationUpdatesPendingIntent);

    Log.d(TAG, "location updates started");
}

protected void stopLocationUpdates() {

    Log.d(TAG, "stopping location updates...");

    mLocationUpdatesEnabled = false;

    LocationServices.FusedLocationApi.removeLocationUpdates(
            mGoogleApiClient,
            mRequestLocationUpdatesPendingIntent);

    Log.d(TAG, "location updates stopped");
}

这一切都很好，很好；当用户按下按钮时，toggleLocationUpdates 会被调用，LocationServices.FusedLocationApi.requestLocationUpdates 会调用我的LocationUpdateService，我可以在其中获取位置。

当我尝试使用 Intent.putExtra(String, String) 将额外的字符串添加到我的 Intent 时，问题就来了：

主要活动类：

...
protected void startLocationUpdates(String username) {
    ....

    // create the Intent to use WebViewActivity to handle results
    Intent mRequestLocationUpdatesIntent = new Intent(this, LocationUpdateService.class);

    //////////////////////////////////////////////////////////////////
    //
    //  When I put this extra, IntentService sees my username extra
    //  but the parcelableExtra `location` == null :(
    // 
    //////////////////////////////////////////////////////////////////

    mRequestLocationUpdatesIntent.putExtra("username", username);
    ...
}
...

编辑 我将下一个句子作为陈述而不是问题开始：“我正在使用......”

我是否使用正确的方法向此位置更新处理 IntentService 发送一些额外的数据，还是有更理智的方法来解决这个问题？

这是一个错误还是只是糟糕的文档？

Answer 1

将 IntentService 与 FusedLocationProviderAPI 结合使用会出现问题。来自标题为接收位置更新的开发者文档：

根据请求的形式，融合的位置提供者 要么调用LocationListener.onLocationChanged() 回调 方法并传递给它一个 Location 对象，或者发出一个PendingIntent 在其扩展数据中包含该位置。精度和频率 的更新受您拥有的位置权限的影响 请求和您在位置请求对象中设置的选项

此外，PendingIntent 用于扩展另一段代码（Google Play 服务中的FusedLocationProviderAPI）的权限，以在您的 apk 中执行其代码。 IntentService 用于启动在您的 apk 范围内定义的服务。

因此，该方法需要实现LocationListener 用于前台更新，或PendingIntent 用于后台更新以及广播接收器。

这是用于从PendingIntent 请求位置更新以及额外值的一些方法的工作示例。

注意：LocalStorage.java 是一个用于存储局部变量的实用程序类，它不是 Android API 的一部分

GPS绘图仪

/**
 * Private helper method to initialize the Google Api Client with the
 * LocationServices Api and Build it for use.
 */
private void initializeGoogleApiClient() {
    mGoogleApiClient = new GoogleApiClient.Builder(mContext)
            .addConnectionCallbacks(this)
            .addOnConnectionFailedListener(this)
            .addApi(LocationServices.API)
            .build();

}

/**
 * Private helper method to determine whether or not GooglePlayServices
 * are installed on the local system.
 *
 * @return services are installed.
 */
private boolean googlePlayServicesInstalled() {
    int result = GooglePlayServicesUtil.isGooglePlayServicesAvailable(mContext);
    return result == ConnectionResult.SUCCESS;
}

/**
 * Private method to build the Api Client for use with the LocationServices API.
 */
private synchronized void buildApiClient() {
    Log.w(TAG, "Building Google Api Client...");
    initializeGoogleApiClient();
}

/**
 * Private method used to connect the ApiClient to the Api hosted by Google for
 * Accessing Locations.
 */
private void connectClient() {
    mGoogleApiClient.connect();
}

 /**
 * User passes in a requested interval polling time in seconds as an
 * integer.
 *
 * @param theAccount is a reference to the parent activity used for updating views.
 */
public void beginManagedLocationRequests(MyAccount theAccount) {
    if (mAccount == null)
        mAccount = theAccount;

    startBackgroundUpdates();

}

/**
 * Public method to end the managed Location Requests.
 */
public void endManagedLocationRequests() {
        endBackgroundUpdates();

}

/**
 * This method handles the switch in polling rates by stopping and then starting once more the
 * background udpates, which in turn sets the interval in another method in the call stack.
 * @param theInterval the desired interval polling rate
 */
public void changeRequestIntervals(int theInterval) {
    mIntentInterval = theInterval;
    if (LocalStorage.getRequestingBackgroundStatus(mContext)) {
        endBackgroundUpdates();
        startBackgroundUpdates();
    }



}

/**
 * Private helper method to build an Intent that will be couple with a pending intent uses
 * for issuing background Location requests.
 *
 * @return theIntent
 */
private Intent buildBackgroundRequestIntent() {
    Intent intent = new Intent(mContext, BackgroundLocationReceiver.class);
    intent.setAction(BACKGROUND_ACTION);
    intent.putExtra(User.USER_ID, mUserID);
    return intent;
}

/**
 * Private helper method used to generate a PendingIntent for use when the User requests background service
 * within the FusedLocationApi until the Interval is changed.
 *
 * @return pendingIntent
 */
private PendingIntent buildRequestPendingIntent(Intent theIntent) {
    Log.w(TAG, "building pending intent");
    return PendingIntent.getBroadcast(mContext, 0, theIntent, 0);
}


/**
 * Private method to start the Location Updates using the FusedLocation API in the background.
 */
private void startBackgroundUpdates() {
    Log.w(TAG, "Starting background updates");
    if (googlePlayServicesInstalled()) {
        LocalStorage.putBackgroundRequestStatus(true, mContext);
        LocalStorage.putLocationRequestStatus(true, mContext);
        registerAlarmManager();
        LocationServices.FusedLocationApi.requestLocationUpdates(mGoogleApiClient, buildLocationRequest(), buildRequestPendingIntent(buildBackgroundRequestIntent()));
    }
}


/**
 * Private method to end background updates.
 */
private void endBackgroundUpdates() {
    Log.w(TAG, "Ending background updates");
    LocalStorage.putBackgroundRequestStatus(false, mContext);
    LocalStorage.putLocationRequestStatus(false, mContext);
    unregisterAlarmManager();
    LocationServices.FusedLocationApi.removeLocationUpdates(mGoogleApiClient, buildRequestPendingIntent(buildBackgroundRequestIntent()));
}

BackgroundLocationReceiver

public class BackgroundLocationReceiver extends BroadcastReceiver {
private static final String TAG = "BLocRec: ";
private static final String UPLOAD_ERROR_MESSAGE = "Background Service to Upload Coordinates Failed.";
private static final String UPLOAD_MESSAGE = "Coordinate Batch Pushed to Database.";

public BackgroundLocationReceiver() {
    //Default, no-arg constructor
}

/**
 * This method handles any location updates received when the app is no longer in focus. Coordinates are
 * stored in the local database and uploaded once every hour.
 * @param context the application context
 * @param intent is the pending intent
 */
@Override
public void onReceive(Context context, Intent intent) {

    if (intent.getAction().matches(GPSPlotter.BACKGROUND_ACTION)) {
        Log.w(TAG, "BLR Received-background");
        Location location = intent.getParcelableExtra(FusedLocationProviderApi.KEY_LOCATION_CHANGED);
        storeLocation(location, context, intent.getStringExtra(User.USER_ID));

    }

编辑 下面的方法构建了调用 requestLocationUpdates() 方法所必需的 LocationRequest

/**
 * Private helper method used to generate a LocationRequest which will be used to handle all location updates
 * within the FusedLocationApi until the Interval is changed.
 *
 * @return locationRequest
 */
private LocationRequest buildLocationRequest() {
    int dateConversion = 1000;
    LocationRequest locationRequest = LocationRequest.create();
    locationRequest.setInterval(mIntentInterval * dateConversion);
    locationRequest.setFastestInterval((mIntentInterval / 2) * dateConversion);
    locationRequest.setPriority(LocationRequest.PRIORITY_HIGH_ACCURACY);
    Log.w(TAG, "Building location request");
    return locationRequest;
}

编辑 经过与 Catherine 的长时间讨论后，我们得出的结论是 google play services library 7.5 存在一个 bug，即当其他 extras 放入 Intent 时，不会处理从 FusedLocationProviderAPI 传递的 Parcelable Extra Location。但是，7.0 确实提供了这种能力。她说她会提交一个bug，我们看看Android团队需要多长时间才能解决