我的一个 iOS 应用程序似乎具有经典 Heisenbug 的症状。该应用程序跟踪用户的家庭位置，因此当用户进入和离开他们的家庭位置时会发生某些事件。
在我测试应用程序时，它运行良好。我进出 aCLCircularRegion并且无论我尝试哪种方式它都有效。它在后台与应用程序一起工作。它适用于关闭的应用程序。它适用于前台的应用程序。它适用于绿色鸡蛋和火腿。
不幸的是，用户报告的问题将延迟 15 分钟左右。用户将进入他们的家，但该事件要到稍后才会发生。在某些情况下，事件根本不会发生。模式似乎是，当用户第一次开始使用应用程序时，它工作得很好。大约一天后，该应用程序似乎无法正常工作。事件被延迟。
我将是第一个承认我不是CLLocationManagerand内部工作的专家CLCircularRegion。我相信我已经正确设置了所有东西，而且我很难弄清楚如何调试这样的东西。
无论如何，我将在这里展示我的一些代码。请记住，这是使用 Xamarin 开发的，因此它使用 C#。
AppDelegate.cs
public static AppDelegate self;
private CLLocationManager locationManager;
private CLCircularRegion[] locationFences;
private void initializeLocationManager()
{
this.locationManager = new CLLocationManager();
// iOS 8 additional permissions requirements
if (UIDevice.CurrentDevice.CheckSystemVersion(8, 0))
{
locationManager.RequestAlwaysAuthorization();
}
locationManager.AuthorizationChanged += (sender, e) =>
{
var status = e.Status;
// Location services was turned off or turned off for this specific application.
if (status == CLAuthorizationStatus.Denied)
{
stopLocationUpdates();
}
else if (status == CLAuthorizationStatus.AuthorizedAlways &&
iOSMethods.getKeyChainBool(OptionsViewController.GENERIC, OptionsViewController.SERVICE_GEOLOCATION_ENABLED))
{
startLocationUpdates();
}
};
if (CLLocationManager.IsMonitoringAvailable(typeof(CLCircularRegion)))
{
locationManager.RegionEntered += (sender, e) =>
{
setRegionStatus(e, "Inside");
};
locationManager.RegionLeft += (sender, e) =>
{
setRegionStatus(e, "Outside");
};
locationManager.DidDetermineState += (sender, e) =>
{
setRegionStatus(e);
};
}
else
{
// cant do it with this device
}
init();
}
public void init()
{
var data = SQL.query<SQLTables.RoomLocationData>("SELECT * FROM RoomLocationData").ToArray();
int dLen = data.Length;
if (dLen > 0)
{
locationFences = new CLCircularRegion[dLen];
for (int x = 0; x < dLen; x++)
{
var d = data[x];
CLCircularRegion locationFence = new CLCircularRegion(new CLLocationCoordinate2D(d.Latitude, d.Longitude), d.Radius, d.SomeID.ToString() + ":" + d.AnotherID.ToString());
locationFence.NotifyOnEntry = true;
locationFence.NotifyOnExit = true;
locationFences[x] = locationFence;
}
}
}
private void setRegionStatus(CLRegionEventArgs e, string status, bool calledFromDidDetermineState = false)
{
string identifier = e.Region.Identifier;
string lastStatus = iOSMethods.getKeyChainItem(OptionsViewController.GENERIC, OptionsViewController.SERVICE_LAST_GEO_STATUS);
if (lastStatus == status + ":" + identifier)
{
return;
}
iOSMethods.setKeychainItem(OptionsViewController.GENERIC, OptionsViewController.SERVICE_LAST_GEO_STATUS, status + ":" + identifier);
string[] split = identifier.Split(new string[] { ":" }, StringSplitOptions.RemoveEmptyEntries);
if (split.Length == 2)
{
try
{
int someID = Convert.ToInt32(split[0]);
int anotherID = Convert.ToInt32(split[1]);
// Notifies our API of a change.
updateGeofenceStatus(someID, anotherID, status);
if (iOSMethods.getKeyChainBool(OptionsViewController.GENERIC, OptionsViewController.SERVICE_GEOLOCATION_NOTIFICATIONS) &&
(status == "Inside" || status == "Outside" || status == "Unknown"))
{
var rm = SQL.query<SQLTables.KeyRoomPropertyData>("SELECT * FROM KeyRoomPropertyData WHERE SomeID ID = ? AND AnotherID = ?",
new object[] { someID, anotherID }).ToArray();
if (rm.Length > 0)
{
if (status == "Unknown")
{
return;
}
var rmD = rm[0];
UILocalNotification notification = new UILocalNotification();
notification.AlertAction = "Geolocation Event";
notification.AlertBody = status == "Inside" ? "Entered " + rmD.SomeName + ": " + rmD.AnotherName :
status == "Outside" ? "Exited " + rmD.SomeName + ": " + rmD.AnotherName :
"Geolocation update failed. If you would like to continue to use Geolocation, please make sure location services are enabled and are allowed for this application.";
notification.SoundName = UILocalNotification.DefaultSoundName;
notification.FireDate = NSDate.Now;
UIApplication.SharedApplication.ScheduleLocalNotification(notification);
}
}
}
catch (Exception er)
{
// conversion failed. we don't have ints for some reason.
}
}
}
private void setRegionStatus(CLRegionStateDeterminedEventArgs e)
{
string state = "";
if (e.State == CLRegionState.Inside)
{
state = "Inside";
}
else if (e.State == CLRegionState.Outside)
{
state = "Outside";
}
else
{
state = "Unknown";
}
CLRegionEventArgs ee = new CLRegionEventArgs(e.Region);
setRegionStatus(ee, state, true);
}
public void startLocationUpdates()
{
if (CLLocationManager.LocationServicesEnabled)
{
init();
if (locationFences != null)
{
foreach (CLCircularRegion location in locationFences)
{
locationManager.StartMonitoring(location);
Timer t = new Timer(new TimerCallback(delegate(object o) { locationManager.RequestState(location); }), null, TimeSpan.FromMilliseconds(500), TimeSpan.FromMilliseconds(-1));
}
}
}
}
public void stopLocationUpdates(bool isRestarting = false)
{
if (locationFences != null)
{
foreach (CLCircularRegion location in locationFences)
{
locationManager.StopMonitoring(location);
}
}
if (!isRestarting)
{
var rooms = SQL.query<SQLTables.KeyRoomPropertyData>("SELECT * FROM KeyRoomPropertyData").ToArray();
foreach (SQLTables.KeyRoomPropertyData room in rooms)
{
// notifies our API of a change
updateGeofenceStatus(room.SomeID, room.AnotherID, "Unknown");
}
}
}
我知道任何人都可以筛选出很多代码，但我现在真的没有很好的理论来说明导致这个错误的原因，或者是否有可能修复 iOS 的限制。
我的一些理论是如果CLLocationManager. PausesLocationUpdatesAutomatically属性可能与它有关，或者与其他属性有关，CLLocationManager例如ActivityType、DesiredAccuracy或DistanceFilter。我将所有这些都保留为默认值，我认为这会很好，但我不太确定。
另一种理论是，在“服务”在后台运行一段时间后，会抛出未捕获的异常。如果是这样的话，iOS 有没有什么可以给我一个堆栈跟踪或什么的？在我所有的测试中，我从来没有遇到过从这段代码中抛出的任何异常，所以我有点怀疑这就是问题所在。不过，在这一点上，我愿意接受任何想法或建议。
另外，请记住，为了让此应用程序按预期方式工作，位置更新事件必须在用户进入或存在时立即发生CLCircularRegion（至少在一分钟左右）。显然，我必须将其留给用户来保持他们的位置服务启用并允许应用程序拥有适当的权限。