I'm running a C# application that needs to encrypt/decrypt files (using NTFS's EFS encryption) on behalf of a specific user account--a user account other than the one under which the application is running.  I didn't want to go through the hassle of firing up a new process (using CreateProcessAsUser) because I'd have to worry about IPC and it'd be less performant.  The question I had was:  is it possible to encrypt/decrypt files as a user other than the one under which the process is running within that process?  I couldn't find any resource on the web that stated an answer definitively, so I wrote some code to try it.  The answer is:  yes.

Here are the steps (it involves a mix of Interop and managed methods):

1. Get a handle to the desired user (the one whose encryption key you want to use) by calling LogonUser.  (You'll need the user's password.)
2. Load the user's profile (aka registry hive) by calling LoadUserProfile.
3. Construct a WindowsIdentity object using the handle provided by the call in step 1.
4. Invoke WindowsIdentity.Impersonate().
5. Perform any file I/O -- it'll be in the context of that user.  The user's encryption key will be used with any File.Encrypt() / FileInfo.Encrypt() invocation.
6. Unload the profile by calling UnloadUserProfile.
7. Close the user handle by calling CloseHandle.

You can do steps 1-4 in the constructor of an IDisposable object and do steps 5-7 in the Dispose() method to ensure proper resource cleanup. 

OK, I'm a bit late to the party, but I now have a great appreciation for the TV series Battlestar Galactica.  I think one of the reasons why I'm so drawn to the show--silly as it may be--is the uncanny resemblances of cast members to real-life politicians.  The similarity between Colonel Saul Tigh and John McCain is pretty well-touted, but equally compelling, I think, is that between former Pakistani President Pervez Musharraf and Commander William Adama.  Come on, who's with me?

JavaScript doesn't have built-in functions to escape or unescape HTML, which may come in handy for certain DOM manipulations or AJAX scripting.  Here are the custom functions I wrote to handle these tasks.  I've tested the implementation with both IE and Firefox.

If you subtract one timestamp from another in Oracle, the result is an interval type.  This is similar to how subtracting a DateTime from another in .NET yields a TimeSpan.  Unfortunately, unlike .NET, Oracle provides no simple equivalent to TimeSpan.TotalSeconds.

Here's the SQL to accomplish it.  Note that fractions of a second are included in the result.

You can't set the next value of a sequence directly in Oracle; you have to drop and recreate the sequence.  Here's a way to do it if you need to set the next value to the largest value in a particular column plus 1:

If you've run a unit test in Visual Studio 2008 that utilizes database connectivity, you may have seen this error when creating a connection object:

Instance names used for writing to custom counters must be 127 characters or less.

The problem crops up when you're running the test within a directory structure with a fairly long name, i.e. you're organizing your code well and giving your projects descriptive names.  Well, this error is punishment for being organized.

There are several Microsoft bug reports on the issue.  One has been ignored, the other closed.

• http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=95049
• http://connect.microsoft.com/VisualStudio/feedback/ViewFeedback.aspx?FeedbackID=176361

There are posts on the web with some workarounds, but none worked for me, perhaps because I'm using Visual Studio 2008?  No matter what I tweaked in .testrunconfig I was still getting the error.  The other approach--shortening the pathname--was really a non-starter.  I wasn't going to compromize well-thought-out organization to get around a Microsoft bug.

So I took a peek at the source of the problem as hinted by the call stack when the error appeared.  It's a method in the internal DbConnectionPoolCounters class in the System.Data.ProviderBase assembly.  Here's the code:

The instance name of the performance counter is being built, in part, from the name of the AppDomain.  When running tests in Visual Studio, this name can be very, very long, especially if your project's home has a long pathname.

The workaround I pursued, then, is to shorten the name of the app domain.  While AppDomain.FriendlyName is a read-only property, and there's no private field of the AppDomain class to change it, there is a private extern method of AppDomain called nSetupFriendlyName.  And, like magic, if you invoke this method and give the app domain a shorter name, problem solved!

Here's the workaround, utilizing a little reflection magic:

When you use the tag, such as on a master page, the HtmlHead control does the rendering work. The results are pretty dreadful; spacing is pretty screwy for one thing. But that's something I can live with.

One thing I can't live with, however, is third party components like DevExpress adding bogus (and redundant!) stylesheet links within the head tag! I wanted to take control of that tag to filter out these tags, but found HtmlHead to be a sealed class. I can't tell you how many times I've tried to correct bad behavior through the well-established OO practice of inheritance only to find a "sealed" wall in my way. Personally, I think that keyword needs to go! But, alas, in this case there is a way to get around the constraint.

I didn't realize this until today, but ASP.NET has a mechanism for overriding how a control renders its content, even if that control is sealed. The magic is in browser adapters. I learned all about it here:

• ASP.NET "Head" Rendering Issues!
• ASP.NET: Override HtmlHead Rendering with ControlAdapters

Well, here's a new one.  Xenocode is offering software virtualization (as opposed to hardware virtualization).  You can use it to render that product installer obsolete.  Bundle all your DLLs, registry changes, and other program files into one self-sufficient EXE.  Pretty cool!

If you add the [TestMethod] attribute to methods in a regular class library, they won't show up in the test view or test editor.  You may see a message "no tests are loaded."  This happens because Visual Studio doesn't look for the attribute in projects that don't have special "I am a test" markings.  If you create a test project from scratch and add the code the problem will go away, but if you've spent time customizing a project, its references, etc., fear not; you don't need to start over.  Edit the .csproj (or .vbproj) file manually and add the following XML as a child of the first <PropertyGroup> element that appears: