I’ve been working on a side project at home the last few days to snipe hard to find restaurant reservations and came across a weird issue I’ve never experienced before while using the .NET framework.

The API I’m calling to find these opportunities returns a DateTime value in the format “2016-11-21T23:00:00-05:00” which could be read as “November 21st, 2016 11:00pm (EST)”. Now while we’ve read the “-05:00” as the timezone offset which equates to the Eastern Time Zone, it appears the .NET framework in the DateTime.Parse() method, takes that as a hint to adjust the value relative to the local timezone instead to “November 22nd, 2016 4:00am”. Can’t imagine any restaurant that is hard to get is open at 4am in the local time.

While on my laptop (using EST) it was working just fine, deploying this to say… an Azure instance (using UTC) introduces just enough frustration to want to kick puppies and pop a small child’s balloon in passing.

I’ve seen it for years in the intellisense popup in Visual Studio without ever looking at it, and now I know why it’s there. The lifesaving DateTimeOffset type works just like the DateTime type, but when fed the value I needed parsed instead sees the timezone value as an offset (thus the type’s name), not an adjustment hint.


Hopefully you see this before you do anything horrible to a young canine or child. For the record, doing either is mean. Asshole.

If you’ve ever had problems trying to target particular .NET frameworks, this cheat sheet put together by @bradwilson@onovotny, and myself a while ago might help. I’m not going to go into depth on about what PCLs are what targeting means with the new frameworks – I think Oren Novotny did a great job over on his blog with his articles…

Below is a static image of it at the time of this blog posting, or you can see the live version which will reflect updates shared here on OneDrive. I suggest opening it in the full fledged Excel as vertically rotated columns don’t render in the online version. If you see any updates that are needed, you can contact me on Twitter @William_Holroyd.

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Ever needed to enumerate certificates installed on a remote machine using just C# and .NET without having to use an agent? It was a problem I’ve had a couple of times now and was able to figure out without the help of MSDN or StackOverflow. I discovered the X509Store class has the power to solve this problem for us as it utilizes the C++ CertOpenStore functionality underneath, but it’s not documented anywhere. As a result, you can use some of the same functionality as the underlying library at the C# level, just by simply doing this…

[gist https://gist.github.com/wholroyd/b7026197c485c6085c60]

It’s evidently the second time I’ve had to do this type of lookup. Luckily I remembered to post the answer back to my own StackOverflow question years ago.

One of the projects I’ve spent the past month working on is a system called Foundation that will eventually become the company’s one stop shop for automation and workflow management. It’ll keep track of everything from services to environments, and the resources they are using underneath in our private cloud and public cloud provider.

In the process of learning Code First Entity Framework for the first time (all previous provides were Data First), I came across an interesting event that you could use to prepare entities before they are committed to the database. For example, you have some entity properties that need to be checked at last minute and possibly changed. You could do the following without having to layer in an abstract DbContextBase between your own context implementation and DbContext that overrides SaveChanges() to perform the same work before calling the same method off the base class…Continue reading

I was asked by another developer recently that was struggling to find a way to provide a Guid that was somehow a hashed value of a given string. The idea was that for any provided string, it would always return the same Guid value. They weren’t concerned with duplicates as that was taken care of using some other set of business logic.

The best thing that came to mind that accomplished this was pushing the string through the MD5 crypto provider and then feeding it into the Guid constructor. The output from the provider is 16 bytes, which just so happens to be the matching array size that the Guid constructor hopes to receive.

Weirdly, neither him or any of the other developers on his team knew about this trick. So I figure it’s something that should be worth posting as it didn’t seem obvious to them, and I guess I should make use of this blog thing every once in a while given that I pay $10/month for it.

I thought I might talk about my pre-blogging days of trying to learn PowerShell when I was trying to avoid learning the VBScript language (I don’t care much for the synatic qualities of the language).

I personally love the PowerShell language as I’m familiar with both C# and PHP, and (at least to me) it looks like a bastard child of the two. The creation and intialization of objects or variables are done the same way as in PHP and has the same method and property accessors that you’d come to recognize in C#. It took me about an hour to pick up the basics of the language, but I just needed to learn how to create classes so I could start causing some damage.

Unfortunately one of the lacking items in PowerShell, even after version 2 is the lack of native classes. The strength of the .NET framework has always been behind the PowerShell language, but it’s never been directly accessible unless you’ve built cmdlets that allow you such power, so your reliance on custom classes have required you to compile them using Visual Studio. Until such time comes around, there are at least a couple of workarounds.

I had pinged a few people around Microsoft to see if it might be possible after reading this blog entry regarding the CTP3 release of PowerShell v2 if the method in how one would dynamically compile C# code into an console application could be used in other ways. It evidently wasn’t quite clear from the original post, so James Brundage from the PowerShell team posted this blog entry showing how you can use the same technique to compile C# based classes on the fly in a script. Pretty neat!

If you’re not a blogger, but know PowerShell pretty well, let me know about any hidden or not-so-known tricks in PowerShell that you know of and I can make an entry for you. Credit will be given!