Kinect Minilogs: Building a Kinect 4 Windows 8 App part 2


Let the confusion begin…

As I start down the path of building my Kinect for Windows (K4W) Windows 8 Application, confusion starts to set in about why I can’t just create a .Net Framework based application in the programming languages of C# or Visual Basic.Net. After all, the last 11 years of Microsoft based computer programming has been rooted in the .Net Framework. We started with the .Net Framework 1.0, and today in the year 2013 we are now in the .Net Framework 4.5. The K4W SDK, and toolkit provide a very simple .Net Framework assembly: Microsoft.Kinect.dll. This assembly is a .Net Framework based assembly, which means as a developer you can quickly and easily build .Net Framework based applications to use the device’s capabilities. The interesting part about this is that this is the only assembly and dll Microsoft provides for interacting with the K4W device.

Question: You mean you can’t write a Kinect 4 Windows 8 application with the .Net Framework?

Well, yes and no. Windows 8 comes in multiple flavors. We have Windows 8 Pro, Windows 8 RT, and Windows 8 Embedded. Windows 8 Pro is the full edition that allows developers to create 2 different type of applications “Desktop” and “Windows Store”. As of right now, these application types are not interchangeable, meaning you can’t develop a “Desktop” which switches to a “Windows Store” type application. You could develop two applications that function alike, thereby giving the impression that the “Windows Store” app is essentially the same as the “Desktop” version, but this is easier said than done. “Windows Store” applications are a new paradigm in programming. The Design model is completely different, as well as the application programming interfaces (Api’s) and libraries used to implement it.

The “Desktop” type of application allows for backwards compatibility to older versions of Windows. This was your typical application that can run in Windows 7, Vista, and before. The “Desktop” type of application supports the full .Net Framework, version 2.0 all the way up to version 4.5. The K4W assembly was written with the .Net Framework 2.0 base, and refreshed to work with the .Net Framework 4.5. As a developer you can take full advantage of this assembly inside your applications.

On the other hand, “Windows Store” applications are based on the new execution engine called the “Windows Runtime” or WinRT for short. The WinRT engine uses a new programming library and set of API’s which include a subset of the .Net Framework. Basically it is the .Net Framework for WinRT. This is not the full fledge .Net Framework 4.5 we developers have become accustom to. The K4W .Net Assembly has not been tested, nor has it been given the official “stamp” of “support” for this framework. There is no guarantee that this assembly will work with this new .Net Framework for WinRT. So, as a developer, if you want a K4W device to work correctly in the official supported way with a “Windows Store” application you have 2 choices.

  1. Wait for Microsoft to release a new Microsoft.Kinect.Dll for WinRT…
  2. Or, create a wrapper library yourself, following the new design and guidelines for the WinRT engine.

One would figure that Microsoft will eventually do this, however Windows 8 is out now, and it could be another 6 months to a year before we see or hear anything about choice #1. Thus, the answer to the above question is yes and no, it depends on the OS you are targeting as a developer.

Continuing on with the other flavors of Windows 8, we have Windows 8 RT. Windows 8 RT only supports “Windows Store” applications, and it must be compiled for the ARM processor chip. This effectively means that the only set of developer API’s available to you are the WinRT api’s and the .Net Framework for WinRT.

Windows 8 Embedded supports both Desktop and Windows Store applications, however it depends upon the configuration of which core Windows OS components are enabled. Windows 8 Embedded allows you to remove or disable core components, such as the Desktop application support, and Windows Store application support and a wide host of other things, like keyboard support, network, printing and etc. Windows 8 Embedded also allows you to control which processor chip you want to support: ARM, Intel, x86, x64, and others. Windows 8 Embedded is the only Windows 8 based OS flavor that allows you to create a “Kiosk” on a touch screen device and completely “harden” it or lock it down.

Question: So you mean to tell me you’re going to write a wrapper around the Microsoft.Kinect.Dll Assembly?

It appears so… I’ve already started down this path. I have the Kinect Sensor Count, and Kinect Audio capabilities working, the rest is to follow. In part 3 I will discuss what it takes to build a wrapper for the WinRT engine. Maybe I will get lucky and the library will compile for ARM as well, this way the wrapper can support all the flavors of Windows 8.

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