Design Guidelines Update: Enum Design

New API Design Guideline: Enums

Brad Abrams — Tue, 18 May 2004 20:33:00 GMT

Coding Standard: Enums standards, fresh and crispy

Ken Brubaker — Tue, 18 May 2004 21:00:00 GMT

Brad Abrams clued us in to the revised Enum usage guidelines.

El a

Juan Roman's WebLog — Wed, 19 May 2004 03:50:00 GMT

re: Design Guidelines Update: Enum Design

Chris Nahr — Wed, 19 May 2004 10:16:00 GMT

You're throwing an Argument[OutOfRange]Exception on invalid enum arguments. Wouldn't an InvalidEnumArgumentException be nicer?

(By the way, do you know why this exception ended up in System.ComponentModel rather than System?)

Link Interface 30.

UnknownReference — Wed, 19 May 2004 18:34:00 GMT

Link Interface 30.

re: Design Guidelines Update: Enum Design

Krzysztof Cwalina — Wed, 19 May 2004 23:22:00 GMT

Chris, the reason we don't want to use InvalidEnumArgumentException is that it's in System.ComponentModel and we don't want to force people who want to catch or throw the exception to import System.ComponentModel. Besides, there is not that much added value in throwing InvalidEnumArgumentException.

The exception is in System.ComponentModel by mistake. I wish it would be in System as it would be a useful general purpose exception.

re: Design Guidelines Update: Enum Design

Uber Braner — Mon, 24 May 2004 17:40:00 GMT

Minor issue (extra semicolon):

if (Foo.SomeFlag == 0;)

re: Design Guidelines Update: Enum Design

Krzysztof Cwalina — Tue, 25 May 2004 01:06:00 GMT

Uber, thanks for pointing out the issue!
I fixed it.

re: Design Guidelines Update: Enum Design

Victor — Sun, 20 Jun 2004 19:00:00 GMT

Hi, can anybody explane me why don't use sufix "Enum".
..."Do not add the suffix ‘flags’ or ‘flag’ to an enum"...
In large project, finding what is what is very hard, or finding letter 's' onda end of Colos.
Tenks

re: Design Guidelines Update: Enum Design

Keith Hill — Mon, 21 Jun 2004 18:45:00 GMT

I think the general idea is that Hungarian notation (suffixing or prefixing) is not necessary in a strongly typed language like C# or VB.NET and just presents visual noise. If you are writing code for internal use only do what you want. But if you want to sell me your .NET library, I won't buy it if it doesn't follow the .NET Guidelines.

re: Design Guidelines Update: Enum Design

Krzysztof Cwalina — Tue, 22 Jun 2004 19:58:00 GMT

Yes, as Keith mentioned, we consider such suffixes to be "visual noise." We only use suffixes when they add substantially more value than they subtract by being inconsistent with the general guidelines (and this is very rare … and subjective). For example we do suffix Collections, Exceptions, EventHandlers, and EventArgs, but that’s about it.

Vote to Remove Enum.IsDefined From All System.Drawing Members

Frank Hileman's WebLog — Thu, 11 Nov 2004 17:48:00 GMT

Le weekly DanWatts — Tue, 30 Nov 2004 21:05:00 GMT

Le weekly DanWatts — Tue, 30 Nov 2004 21:07:00 GMT

Using bitwise operators on enums

dotNet6 — Tue, 15 Mar 2005 13:13:00 GMT

This post explains how to use an enum as a flag system where you can combine several enum values together.

Using bitwise operators on enums

dotNet6 — Tue, 05 Apr 2005 12:59:59 GMT

This post explains how to use an enum as a flag system where you can combine several enum values together.

Why You Should Avoid Using Enumerated Types in XML Web Services

Dare Obasanjo aka Carnage4Life — Wed, 31 Aug 2005 17:15:01 GMT

Why You Should Avoid Using Enumerated Types in XML Web Services

Dare Obasanjo aka Carnage4Life — Wed, 31 Aug 2005 17:28:05 GMT

M G Vinod Kumar’s Technology Blog » Enum Design Guidelines

M G Vinod Kumar’s Technology Blog » Enum Design Guidelines — Mon, 24 Apr 2006 12:37:47 GMT

PingBack from http://mgvinod.wordpress.com/2006/04/24/enum-design-guidelines/

[Design] enumerati

UGbLog di Pierre Greborio — Mon, 26 Jun 2006 13:33:49 GMT

re: Design Guidelines Update: Enum Design

Mikkanu — Thu, 03 Aug 2006 21:00:45 GMT

At the top of the document you say:
<i>Do not extend System.Enum as a base class for a user-defined type.</i>

I've come accross a few instances when creating a custom enum-style class proved to be a great design feature, such as making a custom enumeration type that could perform a certain task. An example would be the System.Drawing.Color class that exposes the colors in a similar fashion to a enumeration.

The issue here is that by creating your own custom enum and not being able to extend the System.Enum class you loose the nice behavior that enums have such as the Parse, GetNames, IsDefined functions..

What is the reason behind this decision?

--
M. Dinescu

re: Design Guidelines Update: Enum Design

Johnny NoGood — Tue, 29 Aug 2006 00:30:45 GMT

You mention everything about Enum's except what I need. We all know how to SET a flag to True, and how to check a flag for True, but once true, how do you set a particular flag to False? I can't seem to find an answer to that ANYWHERE

Krzysztof Cwalina : Clearing Enum Flags

Krzysztof Cwalina : Clearing Enum Flags — Tue, 29 Aug 2006 22:26:54 GMT

PingBack from http://blogs.msdn.com/kcwalina/archive/2006/08/29/ClearingFlagEnum.aspx

re: Design Guidelines Update: Enum Design

kcwalina — Tue, 29 Aug 2006 22:29:22 GMT

Jonny, thanks for pointing out the important topic missing from the enum guidelines. I posted on the subject at http://blogs.msdn.com/kcwalina/archive/2006/08/29/ClearingFlagEnum.aspx

Brenton House : Clearing Enum Flags

Brenton House : Clearing Enum Flags — Wed, 30 Aug 2006 04:32:01 GMT

PingBack from http://weblogs.asp.net/bhouse/archive/2006/08/29/Clearing-Enum-Flags.aspx

C# Enum设计和使用的相关技巧

ASP.NET Chinese Blogs — Fri, 17 Nov 2006 18:42:53 GMT

C# 的 Enum 设计的相关指导在网上有相关文章论述：英文： Design Guidelines Update: Enum Design 中文： C# Idioms: Enum 还是 Enum

Midnight Illusions » Gendarme Tasks: Status Weekly Report

Midnight Illusions » Gendarme Tasks: Status Weekly Report — Mon, 04 Jun 2007 01:15:11 GMT

PingBack from http://nestor.babuine.net/?p=10

re: Design Guidelines Update: Enum Design

Peter Avram — Thu, 02 Aug 2007 08:53:33 GMT

Johnny Nogood asks how to set a flag to false.

You are looking for the other bitwise operators (you know 'or' (|) and 'and' (&) you want 'Conditional Or' (^) and possibly 'complement' (~).

1111 ^ 0010 = 1101 (conditional Or says 'true if only 1 value is true')

Conversely;

1101 ^ 0010 = 1111 which means; if you use the ^ operator; it will toggle the value of that flag.

Complement is slightly different.

~1101 = 0010

~0011 = 1100

it is similar to not; but works on all flags, instead of just 1 boolean value.

possibly better (or worse) explanation found in the VS help, look for "Bitwise Operators"

re: Design Guidelines Update: Enum Design

Steve Dunn — Wed, 07 Nov 2007 00:07:29 GMT

I like to use shift left operators when defining flags, something like:

enum MyEnum

{

Nothing = 0 ,

Something1 = 1 << 0 ,

Something2 = 1 << 1 ,

Something3 = 1 << 2

etc. etc.

}

CatZ Hideout - Handle enums gracefully...

CatZ Hideout - Handle enums gracefully... — Sun, 25 May 2008 05:17:38 GMT

PingBack from http://blog.zoolutions.se/2008/05/25/HandleEnumsGracefully.aspx

When does FlagsAttribute not mean Flags?

C# Nuggets — Thu, 19 Jun 2008 12:54:25 GMT

In the System.Data namespace, there's a ConnectionState enumeration. This has values like Open, Closed,

C# Enum设计和使用的相关技巧

winzheng — Mon, 14 Jul 2008 08:15:13 GMT

设计中遇到图像区域处理方面的问题，想到了枚举，关于枚举的一些技巧，搜存下

re: Design Guidelines Update: Enum Design

blausand — Tue, 18 Nov 2008 15:56:56 GMT

In fact, you mention everything about Enum's except about how actually to add values to enums. If the enum is defined within a close dll, how in the world do i extend it?

thanx for your patient reply :)