Fix: Windows Phone update error 80072f8f

I was setting up a new Lumia phone (with Windows Phone 8.1) and neither phone update, nor the (Here) maps downloads were working. When trying Settings / Phone Update, it was showing error 80072f8f and was pointing to to read more info. However that error code wasn’t listed there. Wonder if there is any page listing all the possible error codes. I find it silly if they have error codes that aren’t documented anywhere officially.

I looked it up on Google (sorry Bing!) and found, which was saying this was related to time/date discrepancy between the phone and the windows update server. Obviously the maps also get their updates via the same system, although the maps update was showing the misleading message that it couldn’t connect to the maps library at that moment.

Although I had set correct timezone, it had wrong date/time, it was set to autoupdate date/time, but forgot that it had no SIM card in it yet. Obviously it doesn’t get these updates from a time server, but from the mobile phone connection provider. Hope Windows 10 phone fixes that and gets the date/time from time server like the one from NIST or from Microsoft that Windows uses on the desktop.

Suggestion: If and while etc. clauses should accept bool? in C#

At TrackingCam app ( I have the following WPF code, where cbTrackingPresenter is a CheckBox control defined in my MainWindow’s XAML:

private void cbTrackingPresenter_Checked(object sender, RoutedEventArgs e)
      if (cbTrackingPresenter.IsChecked == true)

Note the (redundant in my opinion) == true pattern used there. If the == true is omitted, you get the compile-time error "CS0266", with message "Cannot implicitly convert type ‘bool?’ to ‘bool’. An explicit conversion exists (are you missing a cast?)"

Why not make the "if" clause (and "while" and any clause accepts a boolean/condition) more clever and have it accept bool? too? It would only fire the condition if the value is "true" (not if it is false or null) in that case.

You can vote for this suggestion at:

Suggestion: Add Fullscreen and Pin buttons on Titlebar of Windows

Here are some suggestions I’ve sent via Windows Insider feedback app for Windows 10:

1) Add the Fullscreen button to titlebar of ALL windows, not just the ones of Windows 8.1 Store apps. UWP (Universal Windows Platform) apps don’t seem to show zoom button on their titlebar (to make it and any borders autodisappear and take up the whole screenspace) – this is very inconsistent and limiting compared to Win8.1 Store apps.

2) Add a Pin button next to zoom/minimize/restore/close buttons on titlebar of a window to make the window stay on top. User should be able to click a pinned window to bring it to front if there are several ones pinned to top. Currently some tools apps (e.g. task manager) have such functionality, but it is in their menus. It would be handy if all apps had this.
Take care though that any windows that are children (modal or not) of a pinned window also appear on top (pinned) and not behind the app. So a user should be able to pin a child window independently, but when a window is pinned, all its child windows should become pinned with the pin button disabled on them till the parent window is unpinned, or instead better make the pin of the child window be linked to the pin of the parent so that the user can pin/unpin the parent and all child windows from the titlebar pin of anyone of them.

An issue may occur with some programs like TeamViewer that add an extra button on the titlebar of Windows, but they could easily fix their code to see what other buttons there are on the titlebar to not overlap with them (or some compatibility code of Windows could move such buttons a bit more to not overlap in the case of legacy software that has an issue when more buttons than they expect are on the titlebar)

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HowTo: show inner exception message if available, else outer one

Sometimes when you catch an exception in .NET, the message it prints out isn’t very informative, since it is wrapping another exception that had been thrown a bit inner in the code. That exception is in that case accessible via InnerException of the Exception instance.

That inner exception is also an Exception, so one would like to use its Message instead of the outer exception’s one, if an inner exception exists and, only if an inner exception doesn’t exist use the caught exception’s message. Here’s a clean-looking pattern I’ve coined up to achieve this while working on the TrackingCam application:





catch (Exception e)


  MessageBox.Show((e.InnerException ?? e).Message);


the ?? operator returns e.InnerException if it is not null, else falls back to returning e. Those two results are both of type Exception, so you can use Message on them, by putting the ?? operator’s expression in parentheses.

Suggestion: C# static extension methods invokable on class type too

it would be nice if C# supported syntax like:

public static DependencyProperty Register(static DependencyProperty x, string name, Type propertyType, Type ownerType, FrameworkPropertyMetadata typeMetadata)

that is static extension methods for classes, that can be invoked without a class instance (just with the class type), apart from normal extension methods that can be invoked on a class instance.

Then for example I could use it in Silverlight to add to its DependencyProperty class some extra WPF syntax that it currently misses, in order to increase code portability. It would wrap Dr.WPF’s implementation of value coercion for Silverlight’s DependencyProperty. I have the related code at my Compatibility library ( and respective NuGet package (, but the syntactic sugar is missing to achieve source code portability (via WPF and Silverlight projects that include common files via file links) without changes.

Note the "static DependencyProperty" parameter instead of the "this DependencyProperty" one that is used in C# extension methods (or else instead of static maybe they could use other keyword like type or typeof there, but I feel static is more appropriate).

Related discussion:

Also see where somebody mentions "static extension properties" apart from "extension properties". Indeed it is natural that if static extension methods are to be allowed in the future, static extension properties should be added too (to extend a type with [attached] static properties)

You can vote for a related suggestion here:

HowTo: Pause and Resume Speech Recognition with Microsoft engines

At SpeechTurtle application, I’ve just added speech feedback (voicing of a command) when an available command is executed using a mouse click on its name.

That could also help the user learn the expected pronunciation in English in case the speech recognition engine doesn’t understand some of the commands as voiced by the user. One can assume most of what the Speech Synthesis engine outputs to be recognizable by the Speech Recognition engine.

An issue with this approach though, is that the Speech Recognition can be fired accidentally by the speech synthesis commands, if the speech recognition engine doesn’t handle this case automatically, ignoring synthesized speech that is being generated in parallel by the speech engine.

In fact this can also be a security issue, with a malicious agent delivering voice commands to your system via some audio or video file/stream they lure you into listening/watching, or some web page they lure you into visiting (even if a webpage is not malicious, it might have been served and hosting a malicious ad by an ad network).

So, we need some way to pause the speech recognition while speaking, to avoid misfiring of recognition, since from my experience, the speech synthesis and recognition engines from .NET’s System.Speech namespace on recent Windows versions (tried with Windows 10) do have this issue.

In SpeechLib (that SpeechTurtle uses via the SpeechLib NuGet package), I’ve added commands Pause and Resume to the ISpeechRecognition interface (defined in SpeechLib.Models project and respective NuGet package and implemented at SpeechLib.Recognition and SpeechLib.Recognition.KinectV1 projects and NuGet packages).

So, in SpeechTurtle, I can do:

public void SpeakCommand(string command)
  speechRecognition.Pause(); //pause the speech recognizer

Note the pattern used in SpeechRecognition.cs to retry 10 times to pause the speech recognition engine, since errors are thrown if one tries to Stop it or Set its audio input to none while it is trying to perform some recognition.

public void Pause()
  for (int i=0; i<10; i++) //(re)try 10 times
  //(since we wait 100 ms at failure below before retrying, max wait is 1000ms=1sec)
      return; //exit retry loop if succeeded
  catch //catch and ignore any error saying that recognition is currently running
      Thread.Sleep(100); //retry in 100ms

Update 1:

After more testing, it seems the above approach with the loop and try/catch won’t work

if one uses the async versions of Speech Recognition methods, since the exceptions are thrown from another thread. In that case one need to add a global exception handler.

Update 2:

After lots of trial and error, I ended up with this working pattern for Pause and Resume in SpeechLib’s SpeechRecognition.cs (note that paused is a bool(ean) field of that class, defaulting to false and PAUSE_LOOP_SLEEP is a const(ant) int(eger) set to 10 (msec):

public void Pause()
  paused = true;
public void Resume()
  paused = false;

At the constructor of that SpeechRecognition class I do:

  speechRecognitionEngine.RecognizerUpdateReached +=
(s, e) => {
while (paused) Thread

I do a loop at RecognizerUpdateReached event handler to make sure the Speech Recognition

thread is waiting for the pause field to change value back to false. That event occurs after the call to RequestRecognizerUpdate in Pause method (which is done after first setting paused=true there).

HowTo: Get and combine executable path with subfolder and filename

Based on others answers at

here’s an example that shows how to remove the executable name from the path and combine the result with some subfolder and filename:

At my updated version of Hotspotizer (, I’ve just added support for loading a Gesture Collection file at startup, if found at Library\Default.hsjson, by using the following code:

const string DEFAULT_GESTURE_COLLECTION = "Default.hsjson"


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