C# vs VB.NET Case - Sensitivity: what to do

By
Hegel was right when he said that we learn from history that man can never learn anything from history. -- George Bernard Shaw

This one seems to keep coming up, and basically revolves around developer misunderstanding (or more frequently, lack of knowledge) of Naming Guidelines.

The typical question often looks like the following:

"I have a class implented in a c# dll which has two different properties of same name Say "A" and "a".

Now, is their any way to use any one or both of these properties of this class in a vb.net project.because it will give the following error

Error 2 'A' is ambiguous because multiple kinds of members with this name exist in class 'ClassLibrary3.Class1'"

Yes, there is a solution: Write your classes and methods correctly in the first place!

Case Sensitivity
To avoid confusion and guarantee cross-language interoperation, follow these rules regarding the use of case sensitivity:

Do not use names that require case sensitivity. Components must be fully usable from both case-sensitive and case-insensitive languages. Case-insensitive languages cannot distinguish between two names within the same context that differ only by case. Therefore, you must avoid this situation in the components or classes that you create. Do not create two namespaces with names that differ only by case. For example, a case insensitive language cannot distinguish between the following two namespace declarations:

namespace ee.cummings;
namespace Ee.Cummings;

Do not create a function with parameter names that differ only by case. The following example is incorrect.

void MyFunction(string a, string A)

Do not create a namespace with type names that differ only by case. In the following example, Point p and POINT p are inappropriate type names because they differ only by case.

System.Windows.Forms.Point p
System.Windows.Forms.POINT p

Do not create a type with property names that differ only by case. In the following example, int Color and int COLOR are inappropriate property names because they differ only by case.

int Color {get, set}
int COLOR {get, set}

Do not create a type with method names that differ only by case. In the following example, calculate and Calculate are inappropriate method names because they differ only by case.

void calculate()
void Calculate()

There! That wasn't so hard, was it?
Peter has been active on the C# and other MS newsgroups, has had samples at gotdotnet.com (now codegallery.com) that have been downloaded over 56,000 times, and has written numerous articles for eggheadcafe.com, for which he is a co-founder, and MSDNAA sites. He has also been a technical reviewer on books from Prentice Hall, Manning and other publishers. Peter was a Microsoft MVP for 10 years. Peter was born and raised in New York City, and after a stint as a jazz musician playing contrabass with the Robert Hunt Trio, migrated to sunny Florida, where he was hired as a rookie Financial Consultant at Merrill Lynch in Orlando, specializing in Corporate Services. It was at Merrill that Peter realized computers and technology were his forte. He spent his last few years at Merrill developing real – time computerized trading and and stock charting program using advanced technical analysis indicators, some of which are his own inventions. In 1997, he moved on to architect and serve as lead developer on a number of innovative web-based and middleware solutions for the healthcare and financial services industry.

Comments

  1. Anonymous10:32 AM

    Even if you didn't want clr compatibility It would be insane to use or maintain code that does not abide by these standards.

    ReplyDelete
  2. BlackTigerX12:45 PM

    that's what CLS is for, you can use the CLSCompliant attribute

    ReplyDelete
  3. Anonymous3:25 PM

    It would have been nice if C# was case insensitive to begin with.

    Using case as a diferentiator for unrelated properties/variables/functions etc is plain confusing.

    ReplyDelete
  4. peterbromberg10:42 AM

    "It would have been nice": C# follows a respected line of programming languages and even operating system - C, C++, Javascript and UNIX - all of which are case-sensitive.

    They weren't designed by idiots.

    ReplyDelete
  5. RC12:24 PM

    I am running into this problem trying to use a C# class someone else wrote in my vb.net project. The class has 2 properties with the same name but one is capitalized and the other is not. Neither one shows up in my vb.net project. Is there a way to get this to work without modifying the c# class?
    Thanks

    ReplyDelete
  6. peterbromberg12:29 PM

    From reading the post and subsequent comments, one would deduce that the C# class was not written in such a manner as to be eaeily consumed by a case-insesitive language.

    ReplyDelete

Post a Comment

Popular posts from this blog

Some observations on Script Callbacks, "AJAX", "ATLAS" "AHAB" and where it's all going.

By
I've taken a more than cursory interest in the whole Remote Scripting (.NET species) vs. AJAX and now ATLAS discussion, mostly because I started using Remote Scripting since Microsoft first released it, and because I continued to refine it after seeing Brent Ashley's excellent work with JSRS, which was one of the first "real" cross-browser solutions back in 2000 (that's the turn of the Century for you history buffs). Now Bertrand Leroy, a Microsoft guy whose work I like , has authored some very interesting ASP.NET 2.0 script callback stuff that he points to on his blog, and he is obviously (at least, to me he is) involved quite heavily in the development of this new ATLAS infrastructure that they'll preview at PDC. Leroy's most recent post brings to the surface what I agree are the major differences between the "AJAX a - la .NET" approach as popularized by Michael Swartz with his AJAX.NET library, and Leroy's RefreshPanel, the ASP.NET 2.0 b...
Read more

IE7 - Vista: "Internet Explorer has stopped Working"

By
Image
This one was a bitch. All of a sudden for no reason at all, out of the blue, I get this dialog "internet Explorer has stopped working". I didn't install any new software, crap- I didn't do anything! So here I am using FIREFART to go on the internet and find out what to do! Damn! Good thing I've got the sucker on the same machine (I'm not "anti-Firefox", i just don't use it that much except to check my page renderings). The Fix The fix (at least for me): 1) Go into Control Panel, and choose "Internet Options". 2) Under the "Advanced" tab, press the "RESET" button at the lower right: Don't ask me why this happens, or why the fix works. That's a BUG, D00D - I don't care how you slice it!
Read more

FIREFOX / IE Word-Wrap, Word-Break, TABLES FIX

By
One of the most annoying things a developer (who would normally delight in writing code, not futzing with markup) can have is getting rendering issues between different browsers. The two biggest players are of course Internet Exploder and Firefart (as I lovingly like to refer to each). In most cases that's going to take care of 98 percent of your total site traffic. IE has had a proprietary "word-break" style attribute for a long time, and this made it into the CSS 3.0 spec. But that doesn't necessarily help you with Firefox right now. Firefox literally - (and I consider this completely idiotic, since it's been in their bug database for FIVE YEARS) does not have a reliable CSS style element to force table cell content to break in the middle of a word in order to stop the content from expanding your table / div off the page or over other content on the page. Here's a partial fix, which will work for most tables and browsers. The style declaration (I call it m...
Read more

System.Web.Caching.Cache, HttpRuntime.Cache, and IIS Recycles

By
Recently I chimed in on a newsgroup thread to an OP (Original Poster) who was questioning why he was losing Cache items. This individual would load a dataset from the Cache object into a local object to use to perform processing. He had been using httpcontext.current.cache and noticed that sometimes he was not able to get the dataset out of the cache. He tried switching to HttpRuntime.Cache and it seemed to help. The OP claimed that the application is under heavy hits, and once or twice every month he would see this error. He wanted to know why does the HttpContext.Current.Cache call work sometimes, while some other times does not. A couple of posters replied, one of whom is a respected MVP who usually makes very astute, high-quality posts. He posted," The cache is only valid during the life of the request. how is you[sic] code using the cache?" Somebody else (also pretty astute, usually) responded, "Cache is valid during lifetime of application not request.....". W...
Read more

FIX: Requested Registry Access is not allowed (Visual Studio 2008)

By
Symptom: in Visual Studio 2008, you attempt to add a new WebContentForm and associate it with a MasterPage. You receive an error dialog "Requested Reqistry Access is not allowed". Don't ask me what caused this; I'm guessing that the registry keys involved had their access denied due to removal of a previous version of Visual Studio, leaving the new guy (Visual Studio 2008) in the lurch. Here's the fix: Download "subinacl" here . This is a command-line tool that enables administrators to obtain security information about files, registry keys, and services, and transfer this information from user to user, from local or global group to group, and from domain to domain. After installing subinacl.exe (it will be in the C:\Program Files\Windows Resource Kits\Tools folder.), drop to a command prompt and run the following batch file, which you have saved in the same folder with the filename "FIX.bat": subinacl /subkeyreg HKEY_CLASSES_ROOT\VisualStudi...
Read more