AppDev: Something You Should Know by Irena Kennedy

Do you remember the old TreatAs registry setting for COM classes? If you want a quick refresher, check out http://msdn.microsoft.com/library/default.asp?url=/library/en-us/com/html/1d7a1677-738a-4258-9afc-e77bd0dcf40f.asp . Well, TypeForwardedTo...

What do you think is the value of variable result in the code below: string x = "some string here"; bool result = Object.ReferenceEquals("some string here", x); Given that the data type string is a reference type, it may come as a surprise...

Are you curious about how ChangeType is implemented, and whether it is different from a cast? Then read on… First, what is a cast? C# allows classes and structures to create operators that convert the underlying data type to another type....

The other day I was asked the question above, and since others might benefit from seeing the answer, and I’m sharing it with SYSK readers below. Question: I've a need to call a method on a WebForm from within the UserControl that lives on that...

Excel has two very important functions – CEILING and FLOOR that take in two parameters – number and significance. For example, the CEILING function returns number rounded up to the nearest multiple of significance. For example, if you want to avoid using...

The other day I needed to have a dictionary (i.e. fast search by key) class that works on two keys. This is somewhat akin to a three level tree structure -- first level has elements specified by first key, second level – by second key, and the final third...

The other day I came across the question above at http://www.codecomments.com/archive293-2004-7-244806.html , which did not provide the way to accomplish the desired effect. The answer is – yes, you can. Here is how you might go above doing it in .NET...

XPS stands for XML Paper Specification – a specification is designed to provide users with a consistent document appearance regardless of where and how the document is viewed, and will be implemented in Windows Vista™. XPS Documents are fixed-format documents...

Formatting string “C2” explicitly tells to leave two decimals. One could also use “C0” (no decimals), “C1”, “C3”, “C4”. Many believe that there is no difference between the format strings “C” and C2”. While it’s true in the default scenario, it’s only...

Did you know that using WindowsPrincipal.IsInRole is ~40+% slower than doing the same work yourself? Run the code below and you’ll see … Don’t take me wrong – I do not suggest you avoid using IsInRole call; after all a single call is so fast on most computers...

As you know, in VS 2005 you can choose “File System” location option when creating an ASP.NET project. Once selected, how do you switch to running your project as a “normal” IIS web site? The solution is simple: Create a virtual directory in IIS...

Would you like to view items stored in cache, and remove them for testing purposes? How about being able to view the page's view state (in various forms: raw, parsed, and decoded) to help you optimize your state management logic? Does ability to hide...

Both, HttpResponse.WriteFile and HttpResponse.TransmitFile (new in 2.0) write the contents of a file to the output stream. However, WriteFile will load the whole file into the memory while TransmitFile won’t. So, if you’ve been using WriteFile, you may...

Consider the following: static public class MyClass { static public void Method<T>(T x) { . . . MethodX(x); . . . } static private void MethodX(float x) { System.Diagnostics.Debug.WriteLine("Float"); } ...

You may have noticed that there is no release build option for web apps. That’s because all compilation settings are now stored in the <compilation> element of your configuration file under <system.web>. Set debug attribute to false for release...

If not, there is a very good explanation at http://en.wikipedia.org/wiki/Web_2.0 . Here are some main points: To some extent Web 2.0 is a buzzword, incorporating whatever is newly popular on the Web (such as tags and podcasts), and its meaning...

By default, Windows apps (WinForms) are marked with STAThread attribute (see Program.cs). So, if you call System.Threading.WaitHandle.WaitAll passing more than one handle in the array you’ll get an exception “WaitAll for multiple handles on an STA thread...

So, you think you understand when, how and why to override GetHashCode? Then you should be able to answer the following question: will get message box in the code below say “true” or “false”: public class MyClass { private string _param; ...

Did you know that if you type %appdata% in Windows Explorer’s address bar, and press Enter, it’ll open C:\Documents and Settings\UserName\Application Data folder? Likewise, by typing %windir%, you’ll get into whatever folder you’ve installed windows ...

Unquestionably, regions make code much cleaner! But they also led to an explosion of method sizes (in number of lines) and the number of methods per file. Long gone is the “rule of thumb” of early 90s of a function size being equal to the visible screen...