HoloLens – Hello World

What a day it has been… today I unboxed my HoloLens and started my augmented reality adventures.

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After going through the tutorial and learning about Gaze, Gestures and Voice commands and then ofcourse some initial playing around with Holograms, RoboRaid and my first HoloLens Skype call it was time to get ready and start work on my first HoloLens app.

But first I needed to get the right tools:

  • Install the tools on the Windows Dev Center is good place to start, it offers links to the most recent versions of the HoloLens Emulator and Unity HoloLens (currently still in technical preview).
  • Microsoft HoloLens application for Windows is an awesome tool the let’s you live stream the video from your HoloLens to your PC and makes it easy to create videos of your augmented world.

After updating Visual Studio, installing the emulator, installing Unity 3D and creating a Unity account and for good measure, following Unity 3D on Twitter, I figured I was ready to go.

I watched the welcome to Unity video and figured as a coder it might be easier to start with a simple Visual Studio only trial app. Well…. After looking at the DirectX 11 template app  that comes with installed with the SDK and running a colorful cube in the HoloLens emulator I quickly figured I needed an easier start so I build a 2D Universal Windows Application with my “Hello AR World” message. On this page I found how to an over the air WiFi deploy directly from Visual Studio to the HoloLens, nice!

Oh, and after messing around with ‘transparent’ settings for the background of my Window I suddenly remember something Dennis had told me: HoloLens knows no black and so black is considered transparent.


Note: The screen capture shows the transparent window much darker than how you really see it when you wear the HoloLens.

Tip: use Cortana if you need to reboot, just say ‘Hey Cortana’ followed by ‘Reboot’.

Also, I have a feeling my laptop is going to need an upgrade soon… 8GB of memory appears to be barely enough to run the necessary HoloLens emulator, twice I’ve had to restart my machine and make sure that the emulator is started first, before starting other apps.

Next step… building a Unity 3D application… to be continued 🙂


Unlocking VSTS files from a user that left the team

In the past I had used the tf.exe command line tool to unlock files that were locked by a co-worker that had left.

Today I discovered a cool free tool that makes it much easier to delete obsolete workspaces. By deleting the workspace all locks held by the workspace are automatically released.

Go to http://www.attrice.info/cm/tfs/index.htm to download the Attrice Team Foundation Sidekicks.

The Sidekicks tool worked excellent against our online Visual Studio Team Services repository.

VS2015 – Files locked after unit tests

I haven’t figured out yet why it is happening, but after a recent update I suddenly ran into an issue where when I ‘Run All Unit Tests’ in Visual Studio 2015 (Update 3) I end up with locked assemblies. This in turn does not allow me to run any subsequent tests.

Workaround is to kill the unit test processes that are locking the files using a command line (run as administrator account):

taskkill /F /IM vstest* /T


Not the most elegant solution, but it will work for now.

Annotating Entity Framework classes

A golden oldie which I seem to need to lookup everytime I use it: the MetadataTypeAttribute.

When using entity framework to generate POCO classes for my applications I frequently run into the problem that I want to annotate the fields in order to utilize MVC Client-Side validations. The POCO classes are generated so they cannot be modified with loosing the changes upon a refresh of the generated code. The MetadataTypeAtribute offers a solution. Since all generated classes are partial classes we can add a partial class and adorn it with the MetadataTypeAttribute. The attribute points to a new class which mimics the EF class and provides data annotation to describe the rules and properties of each property.



Example IsJsonRequest()

While doing some ASP.NET MVC Json programming today I discovered there is still no standard extension method for checking whether a request specifically wants a Json result.

I wanted to support both the mime type as well as a ‘format’ parameter in the url.

Here is the extension method I wrote:

public static class JsonRequestExtensions
    private const string format = "format";
    private const string json = "json";
    private const string jsonMime = "application/json";

    public static bool IsJsonRequest( this HttpRequestBase request )

        bool isJsonRequest = ( IsRequestedFormatJson( request ) == true
                               IsRequestedMimeTypeJson( request ) == true );

        return isJsonRequest;

    private static bool IsRequestedMimeTypeJson( HttpRequestBase request )
        if ( request.AcceptTypes != null )
            return request.AcceptTypes.Any( t => t.Equals( jsonMime, StringComparison.OrdinalIgnoreCase ) );
        return false;

    private static bool IsRequestedFormatJson( HttpRequestBase request )
        return String.Equals( request[format], json, StringComparison.OrdinalIgnoreCase );

What version of SQL Server are you running?

I needed to know the exact version of our SQL Server installation (in order to determine if test and production were the same). Turns out there is a superb script posted on TechNet to do just that.

You can download it here: https://gallery.technet.microsoft.com/Determining-which-version-af0f16f6

It generates output like this:

--//Your current Microsoft SQL Server information:
Product Version:          12.0.2269.0
Product Name:             SQL Server 2014
Product Level:            RTM + Security update(GDR)
Product Edition:          Developer Edition (64-bit)
Note, if you want to know information about CU, you need to intall
SQL Server 2014 RTM Cumulative Update 10. CU10, <https://support.microsoft.com/en-us/kb/3094220>
                                                  – see KB3094220 to get the Cumulative Update 10
Support Lifecycle stage: Mainstream Support Phase. For additional information refer to 
https://support.microsoft.com/en-us/lifecycle/search?sort=PN&alpha=SQL%20Server&Filter=FilterNO, and Q6, Q18
in the FAQ section of Support Lifecycle page at: https://support.microsoft.com/en-us/lifecycle#gp/lifePolicy
Full information:
Microsoft SQL Server 2014 - 12.0.2269.0 (X64) 
	Jun 10 2015 03:35:45 
	Copyright (c) Microsoft Corporation
	Developer Edition (64-bit) on Windows NT 6.3  (Build 10586: ) (Hypervisor)

--//Recommended updates: 
--### RTM -> QFE or GDR
--### SP  -> QFE or GDR
--### QFE -> QFE
--### GDR -> GDR or QFE
Install the latest service pack:              SP1, <https://support.microsoft.com/en-us/kb/3058865>
Install the latest Cumulative Update (CU) of SP1:  CU6, <https://support.microsoft.com/en-us/kb/3144524>
###### QFE branch updates
12.0.2548 (SQL Server 2014 RTM QFE) http://support.microsoft.com/en-us/kb/3045323
###### GDR branch updates
12.0.2254 (SQL Server 2014 RTM GDR) http://support.microsoft.com/kb/2977315/en-us
12.0.2269 (SQL Server 2014 RTM GDR) http://support.microsoft.com/en-us/kb/3045324
12.0.4213 (SQL Server 2014 SP1 GDR) https://support.microsoft.com/en-us/kb/3070446
Note, if you don’t want to upgrade to latest service pack right now, we recommend you install the latest
Cumulative Update CU13 of SQL Server 2014 RTM.
Install the latest Cumulative Update (CU) of RTM: CU13, <https://support.microsoft.com/en-us/kb/3144517>

--//You can upgrade to any of the following product(s):
SQL Server 2016 Enterprise
SQL Server 2016 Business Intelligence
SQL Server 2016 Standard
SQL Server 2016 Web
SQL Server 2016 Developer

For additional information about supported version and edition upgrades refer to:

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