Removing capabilities from my first Windows Phone app

So, I thought I’d write a Windows Phone app using Visual Studio 2012 the other day. Just a simple little thing, to help me solve my son’s algebra homework without getting into the same binds he does (failure to copy correctly, fumbled arithmetic, you know the thing…)

And I run into my first problem.

The app uses no phone capabilities worth advertising – you know, things like the choice to track your location, so that the app’s install will ask the user “do you want to allow this app to have access to your location”, and you say either “allow”, or “why the hell does a flashlight application need to know where I am?”

And yet, when I run the “Automated Tests” under the Store Test Kit, I get the following:


If you can’t read the image, or you’re searching for this in Google, I’ll tell you that it wants me to know that it’s validated all the capabilities I’m using, and has noticed that I’m using ID_CAP_MEDIALIB and ID_CAP_NETWORKING.

Weird, because I don’t do any networking, and I don’t access any of the phone user’s media.

It’s just my son and me using the app right now, but I can picture some paranoid person wondering why I need access to their media library or networking simply so I can solve the occasional simultaneous or quadratic equation!

Quite frankly, I was mystified, too. Did a bit of searching across the interWebs, but all the articles I found said the same thing – the MediaLib capability must be because you’re using something with the word “Radio” or “Media” in it somewhere (I’m not), and the Networking capability because you’re doing something across the network. I removed all the “using System.Net” lines from all of my code files, but still no joy.

[A quick tip: to find all these rules yourself, look in C:\Program Files (x86)\Microsoft SDKs\Windows Phone\v7.1\Tools\Marketplace for the file “rules.xml”, which will tell you what the capability detection code is looking for]

Nothing in my own code seemed to be actually causing this, so I took a step back and had a look at other references being included by the compiler by default.

System.Net seemed to be an obvious offender, so I removed that, to no effect (quite right, too, because it isn’t the offender, and doesn’t, on its own, cause ID_CAP_NETWORKING to be detected).

No, here’s the culprit:


Microsoft.Expression.Interactions – what on earth is that doing there?

It’s not something I remember including, and quite honestly, when I went looking for it, I’m disappointed to find that it’s associated with Expression Blend, not something I’ve actually used EVER. [Maybe I should, but that’s a topic for another time].

Removing this reference and rebuilding, the XAP tests clear of all capabilities. Which is nice.

So, now I have my “Big Algebra” app in beta test, and it doesn’t tell the user that it’s going to need their media library or their network connection – because it’s not going to need them!

1 thought on “Removing capabilities from my first Windows Phone app”

  1. Arg, this is really annoying! Microsoft.Expression.Interactions.dll causes ID_CAP_MEDIALIB to be included as an app capability. Can´t remove it as I use GotoStateActions and useres are seriously complaining about it as the app doesn´t need access to the media library

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