获取用户在Android中的位置的好方法

大鹏一日同风起，扶摇直上九万里。这篇文章主要讲述获取用户在Android中的位置的好方法相关的知识，希望能为你提供帮助。
问题：尽快将用户的当前位置置于阈值内，同时节省电池电量。
为什么问题是一个问题：首先，android有两个提供商; 网络和GPS。有时网络更好，有时GPS更好。
“更好”是指速度与准确度之比。如果我几乎可以立即获得位置并且不打开GPS，我愿意牺牲几米精度。
其次，如果您要求更新位置更改，则在当前位置稳定时不会发送任何内容。
谷歌有一个确定“最佳”位置的例子：http://developer.android.com/guide/topics/location/obtaining-user-location.html#BestEstimate 但我认为它不应该接近它应该/可能的好。
我有点困惑为什么谷歌没有标准化的位置API，开发者不应该关心位置来自哪里，你应该只指定你想要的东西，手机应该为你选择。
我需要帮助的是：我需要找到一个很好的方法来确定“最佳”位置，也许是一些启发式或者可能通过某些第三方库。
这并不意味着确定最好的提供商！我可能会使用所有提供商并选择其中最好的。
应用程序的背景：该应用程序将以固定间隔收集用户的位置（假设每10分钟左右）并将其发送到服务器。该应用程序应尽可能节省电池，并且位置应具有X（50-100？）米的精度。
目标是以后能够在地图上绘制白天用户的路径，因此我需要足够的准确性。
其他：您认为对于期望和接受的准确度的合理价值是什么？我一直在使用100米接受，并且根据需要使用30米，这要问多少？我希望以后能够在地图上绘制用户的路径。期望100米，接受500米更好吗？
此外，现在我每次更新GPS的时间最长为60秒，如果你在室内的准确度可能超过200米，这个位置太短了吗？
这是我目前的代码，感谢任何反馈（除了缺少错误检查，这是TODO）：

protected void runTask() { final LocationManager locationManager = (LocationManager) context .getSystemService(Context.LOCATION_SERVICE); updateBestLocation(locationManager .getLastKnownLocation(LocationManager.GPS_PROVIDER)); updateBestLocation(locationManager .getLastKnownLocation(LocationManager.NETWORK_PROVIDER)); if (getLocationQuality(bestLocation) != LocationQuality.GOOD) { Looper.prepare(); setLooper(Looper.myLooper()); // Define a listener that responds to location updates LocationListener locationListener = new LocationListener() {public void onLocationChanged(Location location) { updateBestLocation(location); if (getLocationQuality(bestLocation) != LocationQuality.GOOD) return; // We're done Looper l = getLooper(); if (l != null) l.quit(); }public void onProviderEnabled(String provider) {}public void onProviderDisabled(String provider) {}public void onStatusChanged(String provider, int status, Bundle extras) { // TODO Auto-generated method stub Log.i("LocationCollector", "Fail"); Looper l = getLooper(); if (l != null) l.quit(); } }; // Register the listener with the Location Manager to receive // location updates locationManager.requestLocationUpdates( LocationManager.GPS_PROVIDER, 1000, 1, locationListener, Looper.myLooper()); locationManager.requestLocationUpdates( LocationManager.NETWORK_PROVIDER, 1000, 1, locationListener, Looper.myLooper()); Timer t = new Timer(); t.schedule(new TimerTask() {@Override public void run() { Looper l = getLooper(); if (l != null) l.quit(); // Log.i("LocationCollector", // "Stopping collector due to timeout"); } }, MAX_POLLING_TIME); Looper.loop(); t.cancel(); locationManager.removeUpdates(locationListener); setLooper(null); } if (getLocationQuality(bestLocation) != LocationQuality.BAD) sendUpdate(locationToString(bestLocation)); else Log.w("LocationCollector", "Failed to get a location"); }private enum LocationQuality { BAD, ACCEPTED, GOOD; public String toString() { if (this == GOOD) return "Good"; else if (this == ACCEPTED) return "Accepted"; else return "Bad"; } }private LocationQuality getLocationQuality(Location location) { if (location == null) return LocationQuality.BAD; if (!location.hasAccuracy()) return LocationQuality.BAD; long currentTime = System.currentTimeMillis(); if (currentTime - location.getTime() < MAX_AGE & & location.getAccuracy() < = GOOD_ACCURACY) return LocationQuality.GOOD; if (location.getAccuracy() < = ACCEPTED_ACCURACY) return LocationQuality.ACCEPTED; return LocationQuality.BAD; }private synchronized void updateBestLocation(Location location) { bestLocation = getBestLocation(location, bestLocation); }// Pretty much an unmodified version of googles example protected Location getBestLocation(Location location, Location currentBestLocation) { if (currentBestLocation == null) { // A new location is always better than no location return location; } if (location == null) return currentBestLocation; // Check whether the new location fix is newer or older long timeDelta = location.getTime() - currentBestLocation.getTime(); boolean isSignificantlyNewer = timeDelta > TWO_MINUTES; boolean isSignificantlyOlder = timeDelta < -TWO_MINUTES; boolean isNewer = timeDelta > 0; // If it's been more than two minutes since the current location, use // the new location // because the user has likely moved if (isSignificantlyNewer) { return location; // If the new location is more than two minutes older, it must be // worse } else if (isSignificantlyOlder) { return currentBestLocation; } // Check whether the new location fix is more or less accurate int accuracyDelta = (int) (location.getAccuracy() - currentBestLocation .getAccuracy()); boolean isLessAccurate = accuracyDelta > 0; boolean isMoreAccurate = accuracyDelta < 0; boolean isSignificantlyLessAccurate = accuracyDelta > 200; // Check if the old and new location are from the same provider boolean isFromSameProvider = isSameProvider(location.getProvider(), currentBestLocation.getProvider()); // Determine location quality using a combination of timeliness and // accuracy if (isMoreAccurate) { return location; } else if (isNewer & & !isLessAccurate) { return location; } else if (isNewer & & !isSignificantlyLessAccurate & & isFromSameProvider) { return location; } return bestLocation; }/** Checks whether two providers are the same */ private boolean isSameProvider(String provider1, String provider2) { if (provider1 == null) { return provider2 == null; } return provider1.equals(provider2); }

答案看起来我们正在编写相同的应用程序; -) 这是我目前的实施。我仍处于GPS上传应用程序的beta测试阶段，因此可能会有许多改进。但到目前为止似乎工作得很好。

/** * try to get the 'best' location selected from all providers */ private Location getBestLocation() { Location gpslocation = getLocationByProvider(LocationManager.GPS_PROVIDER); Location networkLocation = getLocationByProvider(LocationManager.NETWORK_PROVIDER); // if we have only one location available, the choice is easy if (gpslocation == null) { Log.d(TAG, "No GPS Location available."); return networkLocation; } if (networkLocation == null) { Log.d(TAG, "No Network Location available"); return gpslocation; } // a locationupdate is considered 'old' if its older than the configured // update interval. this means, we didn't get a // update from this provider since the last check long old = System.currentTimeMillis() - getGPSCheckMilliSecsFromPrefs(); boolean gpsIsOld = (gpslocation.getTime() < old); boolean networkIsOld = (networkLocation.getTime() < old); // gps is current and available, gps is better than network if (!gpsIsOld) { Log.d(TAG, "Returning current GPS Location"); return gpslocation; } // gps is old, we can't trust it. use network location if (!networkIsOld) { Log.d(TAG, "GPS is old, Network is current, returning network"); return networkLocation; } // both are old return the newer of those two if (gpslocation.getTime() > networkLocation.getTime()) { Log.d(TAG, "Both are old, returning gps(newer)"); return gpslocation; } else { Log.d(TAG, "Both are old, returning network(newer)"); return networkLocation; } }/** * get the last known location from a specific provider (network/gps) */ private Location getLocationByProvider(String provider) { Location location = null; if (!isProviderSupported(provider)) { return null; } LocationManager locationManager = (LocationManager) getApplicationContext() .getSystemService(Context.LOCATION_SERVICE); try { if (locationManager.isProviderEnabled(provider)) { location = locationManager.getLastKnownLocation(provider); } } catch (IllegalArgumentException e) { Log.d(TAG, "Cannot acces Provider " + provider); } return location; }

编辑：这是从位置提供者请求定期更新的部分：

public void startRecording() { gpsTimer.cancel(); gpsTimer = new Timer(); long checkInterval = getGPSCheckMilliSecsFromPrefs(); long minDistance = getMinDistanceFromPrefs(); // receive updates LocationManager locationManager = (LocationManager) getApplicationContext() .getSystemService(Context.LOCATION_SERVICE); for (String s : locationManager.getAllProviders()) { locationManager.requestLocationUpdates(s, checkInterval, minDistance, new LocationListener() {@Override public void onStatusChanged(String provider, int status, Bundle extras) {}@Override public void onProviderEnabled(String provider) {}@Override public void onProviderDisabled(String provider) {}@Override public void onLocationChanged(Location location) { // if this is a gps location, we can use it if (location.getProvider().equals( LocationManager.GPS_PROVIDER)) { doLocationUpdate(location, true); } } }); // //Toast.makeText(this, "GPS Service STARTED", // Toast.LENGTH_LONG).show(); gps_recorder_running = true; } // start the gps receiver thread gpsTimer.scheduleAtFixedRate(new TimerTask() {@Override public void run() { Location location = getBestLocation(); doLocationUpdate(location, false); } }, 0, checkInterval); }public void doLocationUpdate(Location l, boolean force) { long minDistance = getMinDistanceFromPrefs(); Log.d(TAG, "update received:" + l); if (l == null) { Log.d(TAG, "Empty location"); if (force) Toast.makeText(this, "Current location not available", Toast.LENGTH_SHORT).show(); return; } if (lastLocation != null) { float distance = l.distanceTo(lastLocation); Log.d(TAG, "Distance to last: " + distance); if (l.distanceTo(lastLocation) < minDistance & & !force) { Log.d(TAG, "Position didn't change"); return; } if (l.getAccuracy() > = lastLocation.getAccuracy() & & l.distanceTo(lastLocation) < l.getAccuracy() & & !force) { Log.d(TAG, "Accuracy got worse and we are still " + "within the accuracy range.. Not updating"); return; } if (l.getTime() < = lastprovidertimestamp & & !force) { Log.d(TAG, "Timestamp not never than last"); return; } } // upload/store your location here }

需要考虑的事项：

不要经常请求GPS更新，它会耗尽电池电量。我目前使用30分钟默认为我的应用程序。
添加“到最后已知位置的最小距离”检查。如果没有这个，当GPS不可用时，你的点将“跳转”，并且位置正从手机信号塔进行三角测量。或者您可以检查新位置是否超出上一个已知位置的准确度值。

另一答案根据我的经验，我发现最好使用GPS定位，除非它不可用。我不太了解其他位置提供商，但我知道对于GPS，有一些技巧可以用来给出一些贫民窟精确度量。海拔通常是一个标志，所以你可以检查荒谬的价值观。 Android位置修复程序有准确度衡量标准。此外，如果您可以看到使用的卫星数量，这也可以指示精度。
【获取用户在Android中的位置的好方法】一个有趣的方法来更好地了解准确性可能是非常迅速地要求一组修复，例如~1 /秒持续10秒然后再睡一两分钟。我去过的一次谈话导致相信一些Android设备无论如何都会这样做。然后你会淘汰异常值（我听过这里提到的卡尔曼滤波器）并使用某种中心策略来获得单一修复。
显然，你到达这里的深度取决于你的要求有多难。如果您对获得最佳位置有特别严格的要求，我想您会发现GPS和网络位置与苹果和橙子相似。 GPS也可能因设备而异。
另一答案最近重构了获取代码的位置，学习了一些好的想法，最后实现了一个比较完善的库和Demo。
@Gryphius的回答很好

https://github.com/bingerz/FastLocation/blob/master/fastlocationlib/src/main/java/cn/bingerz/fastlocation/FastLocation.java

完成实施：qazxswpoi
1.感谢@Gryphius解决方案的想法，我也分享了完整的代码。
2.每次请求完成位置，最好删除更新，否则手机状态栏将始终显示定位图标
另一答案Skyhook（http://www.skyhookwireless.com/）的位置提供商比Google提供的标准提供商快得多。它可能正是你要找的东西。我不隶属于他们。
另一答案要为您的应用选择正确的位置提供商，您可以使用Criteria对象：

Criteria myCriteria = new Criteria(); myCriteria.setAccuracy(Criteria.ACCURACY_HIGH); myCriteria.setPowerRequirement(Criteria.POWER_LOW); // let Android select the right location provider for you String myProvider = locationManager.getBestProvider(myCriteria, true); // finally require updates at -at least- the desired rate long minTimeMillis = 600000; // 600,000 milliseconds make 10 minutes locationManager.requestLocationUpdates(myProvider,minTimeMillis,0,locationListener);

阅读requestLocationUpdates的文档，了解有关如何考虑参数的更多详细信息：

可以使用minTime和minDistance参数来控制通知的频率。如果minTime大于0，则LocationManager可能会在位置更新之间休息minTime毫秒以节省电量。如果minDistance大于0，则仅当设备移动minDistance米时才会广播位置。要尽可能频繁地获取通知，请将两个参数都设置为0。

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