.net Brainwork

04 Apr 2013

Windows Store App: Ways to send parameters when navigating between ViewModels

Tags: Windows 8, Windows RT
Posted in Windows 8, Windows RT | Leave a comment

This is a quick reference for those starting on Windows Store Application development. If you are using Caliburn.Micro (if not, you probably should), you’re certain to require passing data between ViewModels/Screens. I’ll expose two ways you can go for to achieve this. Assuming you have a local reference/dependency for Caliburn’s INavigationService, first approach is to call the NavigateToViewModel method (the example is in the context of a ICommand.Execute()-type call):

public void Execute(string vehicleNameParameter)
{
    navigationService.NavigateToViewModel<TargetPageViewModel>(vehicleNameParameter);
}

public void Execute(string vehicleNameParameter)

{

navigationService.NavigateToViewModel<TargetPageViewModel>(vehicleNameParameter);

}

The method accepts one parameter, and that’s where you should send your data. In the destination ViewModel, on the other hand, in order to access the data, you need to (more…)

16 Mar 2013

VS2012 XMTransposeMatrix memory alignment error

Tags: C#, DirectX
Posted in WPF | Leave a comment

Working on a simple 3D engine I occasionally stumbled upon an invalid access exception on a XMMATRIX transpose operation while invoking rendering in dirty state shapes in my scene. At first I thought it was something on my side, and rolled back some code to sort things out. But I realized the issue persisted. I ended up reducing the scope scope of the problem to the the XMTransposeMatrix call. Here’s an extract of the DirectXMatrix library code where the error is being raised:

#elif defined(_XM_SSE_INTRINSICS_)
// x.x,x.y,y.x,y.y
<strong>XMVECTOR vTemp1 = _mm_shuffle_ps(M.r[0],M.r[1],_MM_SHUFFLE(1,0,1,0));</strong>
// x.z,x.w,y.z,y.w
XMVECTOR vTemp3 = _mm_shuffle_ps(M.r[0],M.r[1],_MM_SHUFFLE(3,2,3,2));
// z.x,z.y,w.x,w.y

#elif defined(_XM_SSE_INTRINSICS_)

// x.x,x.y,y.x,y.y

<strong>XMVECTOR vTemp1 = _mm_shuffle_ps(M.r[0],M.r[1],_MM_SHUFFLE(1,0,1,0));</strong>

// x.z,x.w,y.z,y.w

XMVECTOR vTemp3 = _mm_shuffle_ps(M.r[0],M.r[1],_MM_SHUFFLE(3,2,3,2));

// z.x,z.y,w.x,w.y

SSE needs data to be aligned on 16 bytes boundary, not 16 bits, that’s why the shifting is taking place there. (more…)

18 Jan 2013

You do not have permissions to create a new team project – Here’s why

Tags: Team Foundation Server, Visual Studio
Posted in WPF | Leave a comment

There is a good chance you stumble into this error message in VS 2010, while accessing a TFS 2012 instance. If you do, you should use the Visual Studio Team Explorer 2012 (included in all Visual Studio editions or may be separately downloaded) to create a team project on a TFS 2012 server. If you use VS 2010, you will get an error about not having permission. The error message is very misleading, because it’s not a problem with your permissions.

16 Jan 2013

Remove SQL Server database from single-user mode

Tags: SQL Server, SQL Server 2012
Posted in SQL Server | Leave a comment

Just another friendly tip that I believe can be useful to many. When setting up a local testing environment I installed TFS 2012 with database files placed on a redundant raid array. To do this, I ran a small script to make the required changes to TFS databases file paths, but when I took them online I their names had “Single User” next to them, and the icon changed as well. This happened to me once, so I thought of immortalizing the “fix”. i say “fix” because this is actually a fail safe from the engine. This happens because SQL (more…)

27 Nov 2012

Using the .NET 4 Task class in WPF

Tags: .NET Framework, .NET Framework 4.0, C#, Silverlight, WPF
Posted in .NET Framework 4.0, C#, WPF | Leave a comment

Here’s a quick example on how to implement an asynchronous call in WPF using the System.Threading.Tasks.Task class. Keep in mind that underneath, the call will still end up in a thread pool, as opposed to a ThreadPool approach.

public void StartAsyncTask()
{
     Task&lt;int&gt;.Factory
                .StartNew(DoAsynkWork)
                .ContinueWith(ValidateResults,
                    TaskScheduler.FromCurrentSynchronizationContext());
}

private int DoAsyncWork()
{
        // Do work and return result.
}

private void ValidateResults(Task&lt;int&gt; task)
{
        if (task.IsFaulted)
        {
                return;
        }

        var result = task.Result;

        // Do some UI Thread stuff...
}

public void StartAsyncTask()

{

Task<int>.Factory

.StartNew(DoAsynkWork)

.ContinueWith(ValidateResults,

TaskScheduler.FromCurrentSynchronizationContext());

}

private int DoAsyncWork()

{

// Do work and return result.

}

private void ValidateResults(Task<int> task)

{

if (task.IsFaulted)

{

return;

}

var result = task.Result;

// Do some UI Thread stuff...

}

The trick is to use TaskScheduler.FromCurrentSynchronizationContext() to make sure we can work in the UI Thread. ContinueWith sets up a follow-up call to do some final work and that’s it.

17 Oct 2012

Guide to building a Home Theater PC – Part III

Posted in General | Leave a comment

On the previous article we’ve set up the basic settings for the OS and set up MediaPortal as media frontend solution for our HTPC. This time around I’ll cover all the tools required for the perfect movie and tv show download automation. The downloader: SabNZBd SABnzbd is an Open Source Binary Newsreader, incredibly easy to use, and works practically everywhere. It makes Usenet as simple and streamlined as possible by automating everything. All you have to do is add an .nzb. SABnzbd takes over from there, where it will be automatically downloaded, verified, repaired, extracted and filed away with zero human interaction. (more…)

16 Oct 2012

Guide to building a Home Theater PC – Part II

Posted in General | Leave a comment

After going into a detailed Home Theater PC assembly, it’s now time to delve into the most important aspect of the HTPC experience: the software. You can have the biggest rig on earth, but if you’re still on DOS, it doesn’t do much to you. So this second part of my guide will cover all the essentials to get you up and running in style with the best free/open source software available. Starting with the OS, since I’ll be covering a windows HTPC solution, I recommend using Windows 7. Either version will be ok, since we won’t need any specific (more…)

11 Oct 2012

How to fix Onkyo SR875 display malfunctioning

Posted in General | 2 Comments

It’s been 9 months since my last post. Guess wedding preparations and side projects took more than their share of my free time. It’s hopefully all about to change now, since I now bear the wedding ring and it’s time to go back to the roots! Just before going on honeymoon my Onkyo SR875 AV Receiver’s display ceased to work. Other than not seeing the usual info on the screen, the receiver worked fine. Of course this little big issue got me worried since the warranty period is over and I would need to take it to the nearest servicing (more…)

24 Jan 2012

Tip: Problems debugging the .Net Framework

Posted in WPF | Leave a comment

I’ve recently developed a major infrastructure that deals with serialization/de-serialization of complex application documents. One of the main challenges I had, was handling document files from another application. Although both source and consumer application share a common business library, there were also app-specific types serialized along with everything else. So to be able to correctly interpret the data being serialized and be able to act on every step, I had to inevitably delve into the framework 4.0 source code, mainly the ObjectManager. The problem: It came to my understanding that there are a number of issues developers face when setting (more…)

17 Oct 2011

Guide to building a Home Theater PC – Part I

Tags: General, HTPC
Posted in General | 3 Comments

Background As a home cinema enthusiast and casual player, I always fed the idea of having a high quality surround system on my living room. That opportunity presented itself when both me and my fiance decided to buy our first apartment about two years ago, so long before that I started envisioning and planning on the best possible configuration. When our building reached construction phase, my goal was to setup a 7.1 audio channel system. Issue is, unless you are a lucky enough to have a home-theater-friendly wife, you are in for tough resistance. So there were several things that had to be thought (more…)