Rewriting Existing Functionality in the .NET Base Class Library

Question

Relating to another question I asked yesterday with regards to logging I was introduced to TraceListeners which I'd never come across before and sorely wish I had. I can't count the amount of times I've written loggers needlessly to do this and nobody had ever pointed this out or asked my why I didn't use the built in tools. This leads me to wonder what other features I've overlooked and written into my applications needlessly because of features of .NET that I'm unaware of.

Does anyone else have features of .NET that would've completely changed the way they wrote applications or components of their applications had they only known that .NET already had a built in means of supporting it?

It would be handy if other developers posted scenarios where they frequently come across components or blocks of code that are completely needless in hindsight had the original developer only known of a built in .NET component - such as the TraceListeners that I previously noted.

This doesn't necessarily include newly added features of 3.5 per se, but could if pertinent to the scenario.

Edit - As per previous comments, I'm not really interested in the "Hidden Features" of the language which I agree have been documented before - I'm looking for often overlooked framework components that through my own (or the original developer's) ignorance have written/rewritten their own components/classes/methods needlessly.

Answer 1

You should take a look at this post

http://stackoverflow.com/questions/9033/hidden-features-of-c

Answer 2

Also:

• http://stackoverflow.com/questions/54929/hidden-features-of-asp-net
• http://stackoverflow.com/questions/102084/hidden-features-of-vb-net
• http://stackoverflow.com/questions/181613/hidden-features-of-f

Answer 3

The yield keyword changed the way I wrote code. It is an AMAZING little keyword that has a ton of implications for writing really great code.

Yield creates "differed invoke" with the data that allows you to string together several operations, but only ever traverse the list once. In the following example, with yield, you would only ever create one list, and traverse the data set once.

FindAllData().Filter("keyword").Transform(MyTransform).ToList()

The yield keyword is what the majority of LINQ extensions were built off of that gives you the performance that LINQ has.

Answer 4

The most frequently overlooked feature I came across is the ASP.net Health Monitoring system. A decent overview is here: http://aspnet.4guysfromrolla.com/articles/031407-1.aspx

I know I personally recreated it on several apps before I actually saw anything in a book or on the web about it.

I spoke to someone at a conference one time and asked about it. They told me the developer at MS had bad communication skills so it was largely left undocumented :)

Answer 5

I re-wrote the System.Net.WebClient class a while back. I was doing some web scraping and started my own class to wrap HttpWebRequest/HttpWebReponse. Then I discovered WebClient part way through. I finished it anyway because I needed functionality that WebClient does not provide (control of cookies and user agent).

Something I'm thinking about re-writing is the String.Format() method. I want to reflect the code used to parse the input string and mimic it to build my own "CompiledFormat" class that you can use in a loop without having to re-parse your format string with each iteration. The result will allow efficient code like this:

var PhoneFormat = new CompiledFormat("({0}){1}-{2}x{3}");
foreach (PhoneNumber item in MyPhoneList)
{
    Console.WriteLine(PhoneFormat.Apply(PhoneNumber.AreaCode, PhoneNumber.Prefix, PhoneNumber.Number, PhoneNumber.Extension));
}

Update:
This prompted me to finally go do it. See the results here: http://stackoverflow.com/questions/761121/performance-issue-building-a-string