Why we don’t recommend using List<T> in public APIs

re: Why we don’t recommend using List in public APIs

Rob P — Mon, 26 Sep 2005 19:43:16 GMT

List<T> has so much useful stuff on it though :) Stuff, I might add, that is probably implemented using only members from IList (Find, FindAll, etc).

I guess we can wait for c# 3 and just extend IList<T> to have all the methods of List<T> we want.

re: Why we don’t recommend using List in public APIs

Kristoffer Henriksson — Mon, 26 Sep 2005 19:54:04 GMT

Is there a replacement generic type that you recommend using instead?

re: Why we don’t recommend using List in public APIs

kcwalina — Mon, 26 Sep 2005 23:23:45 GMT

We recommend using Collection<T>, ReadOnlyCollection<T>, or KeyedCollection<TKey,TItem> for outputs and properties and interfaces IEnumerable<T>, ICollection<T>, IList<T> for inputs.

If you need the List<T> useful APIs on your public API, just inherit from Collection<T> and add these APIs.

re: Why we don’t recommend using List in public APIs

bowerm — Thu, 29 Sep 2005 19:11:05 GMT

Interesting. So you could say Collection<T> is the Generic equivalent of CollectionBase from v1.1?

re: Why we don’t recommend using List in public APIs

kcwalina — Fri, 30 Sep 2005 07:53:09 GMT

Yes, Collection<T> is just a better CollectionBase. See http://blogs.msdn.com/kcwalina/archive/2005/09/23/Collections.aspx for more details.

re: Why we don’t recommend using List<T> in public APIs

Michael Primeaux — Wed, 26 Apr 2006 23:42:59 GMT

What is the recommended pattern for implementing a synchronized class that inherits from Collection<T>? For example, I want to implement a SyncRoot property of type ReaderWriterLock. I do see where I can override (protected) the methods InsertItem, RemoveItem, ClearItems, and SetItem. However, I do not see an override for GetItem.

FAQ: Why does DoNotExposeGenericLists say that I should expose Collection<T> instead of List<T>? [David Kean]

Visual Studio Managed Code Analysis (FxCop) — Fri, 28 Apr 2006 00:43:33 GMT

DoNotExposeGenericLists fires when I publicly expose a List&lt;T&gt; via a field, method, property, or...

re: Why we don’t recommend using List<T> in public APIs

Roger — Wed, 06 Sep 2006 16:15:58 GMT

<<We recommend using Collection<T>, ReadOnlyCollection<T>, or KeyedCollection<TKey,TItem> for outputs and properties and interfaces IEnumerable<T>, ICollection<T>, IList<T> for inputs. >>

Lets say I have my own collection of Persons deriving from collection<t> where I've added some new functionality... Do you mean that I should return a collection<t> instead of my derived collection type in a method returning Persons? Why? Harder for the clients to get hold of my collection specific API. Or do I misunderstand you?

re: Why we don’t recommend using List<T> in public APIs

Perry Rapp — Tue, 12 Sep 2006 21:29:24 GMT

Let me ask again a great question above (Michael's), which was apparently never answered:

What is the recommended pattern for implementing a synchronized class that inherits from Collection<T>?

Data Access Layer 101

StrangeLog - Il blog di Andrea Saltarello — Thu, 14 Sep 2006 16:20:50 GMT

Data Access Layer 101

StrangeLog - Il blog di Andrea Saltarello — Thu, 14 Sep 2006 16:21:43 GMT

Forse ha ragione David: la mia risposta al post di Giulio (per quanto sintetica e quindi non esaustiva) non

Data Access Layer 101

StrangeLog - Il blog di Andrea Saltarello — Thu, 14 Sep 2006 16:24:32 GMT

re: Why we don’t recommend using List<T> in public APIs

kcwalina — Thu, 14 Sep 2006 22:11:42 GMT

Michael and Perry, I will try to write some detailed guidelines on synchronization and post them to this blog. Unfortunatelly I am swampped right now and this is a relativelly large project. But quickly, in most scenarios, we recommend you wrap all collections and other components that need to be synchronized. In some other scenarios where the only resource that needs to be synchronized is the collection, I would simply inherit and add a sync root, optionally override the for protected members that modify Collection<T> and synchronize there.

FAQ: Why does DoNotExposeGenericLists recommend that I expose Collection<T> instead of List<T>? [David Kean]

Visual Studio Managed Code Analysis (FxCop) — Thu, 12 Oct 2006 19:51:29 GMT

DoNotExposeGenericLists fires when I publicly expose List<T> via a field, method, property, or

re: Why we don’t recommend using List in public APIs

Andreas — Tue, 17 Oct 2006 19:40:48 GMT

What would you recommend in this scenario:

We have a class with an abstract method that is intended to be subclassed by the user of our framework. The method to override should produce a list of items that are determined in an application specific way.

Is it ok for this method to look like this:

protected abstract IEnumerable<Item> GetItems(...);

> We recommend using ... IEnumerable<T>, ... for inputs.

I would argue that the output from this overridden method is the input to our API, and as such IEnumerable has the least requirements for the implementation.

How about users that use other languages than C#and VB? As far as I know, generics are CLS compliant. Can everybody override such a method?

re: Why we don’t recommend using List in public APIs

An Phu — Wed, 16 May 2007 00:22:31 GMT

What are your recommendations in a webservice context?

Haugerns Development Escapades » Blog Archive » .Net Collection<T> vs. List<T>

Mon, 03 Dec 2007 00:21:21 GMT

PingBack from http://www.haugern.net/blog/net-collectiont-vs-listt/

re: Why we don’t recommend using List in public APIs

Vladimir Kelman — Tue, 01 Apr 2008 19:51:42 GMT

Hi Krzysztof! Sorry for putting it here, but don't you think that there is a small bug in http://blogs.msdn.com/fxcop/archive/2006/04/27/585476.aspx example they put to explain your post? (Comments not allowed there). In class Person they have

private AddressCollection _Addresses = new AddressCollection();

But class AddressCollection does not have such parameterless constructor. The only one available takes Person owner parameter:

public AddressCollection(Person owner)

Elegant Code » Replace your Collections with IEnumerable<T>

Elegant Code » Replace your Collections with IEnumerable<T> — Mon, 07 Apr 2008 23:16:39 GMT

PingBack from http://elegantcode.com/2008/04/07/replace-your-collections-with-ienumerablet/

re: Why we don’t recommend using List in public APIs

kcwalina — Tue, 08 Apr 2008 03:20:40 GMT

Vladimir,

thanks for pointing it out. I will email the fxcop team about it.

The Missing .NET #2: Collection<T> AddRange() | Jason Kemp .ca

The Missing .NET #2: Collection<T> AddRange() | Jason Kemp .ca — Wed, 09 Apr 2008 19:03:45 GMT

PingBack from http://www.ageektrapped.com/blog/the-missing-net-2-collectiont-addrange/

Public APIlerde List by eser.ozvataf.com

Public APIlerde List by eser.ozvataf.com — Thu, 25 Sep 2008 21:46:07 GMT

PingBack from http://eser.ozvataf.com/blog/29

Frage zum string [] | hilpers

Frage zum string [] | hilpers — Sat, 17 Jan 2009 20:45:08 GMT

PingBack from http://www.hilpers.com/1205717-frage-zum-string

Supporto per estrapolare dati | hilpers

Supporto per estrapolare dati | hilpers — Sat, 17 Jan 2009 23:53:05 GMT

PingBack from http://www.hilpers.it/2657139-supporto-per-estrapolare-dati

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Colllection-Klasse casten | hilpers — Sun, 18 Jan 2009 13:41:22 GMT

PingBack from http://www.hilpers.com/1174313-colllection-klasse-casten

ArrayList oder String.Concat() ? | hilpers

ArrayList oder String.Concat() ? | hilpers — Tue, 20 Jan 2009 18:37:14 GMT

PingBack from http://www.hilpers.com/269060-arraylist-oder-string-concat

Lista de Generics con Eventos | hilpers

Lista de Generics con Eventos | hilpers — Tue, 20 Jan 2009 22:06:21 GMT

PingBack from http://www.hilpers-esp.com/443042-lista-de-generics-con-eventos

re: Why we don’t recommend using List in public APIs

Phani — Mon, 09 Mar 2009 20:09:46 GMT

What is the general recommendation for using List in WCF Operations?

re: Why we don’t recommend using List in public APIs

ae — Tue, 27 Oct 2009 10:17:18 GMT

what is recommended in frk 3.5 ?? thanks.

Why we don’t recommend using List<T> in public APIs

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List<T> in public APIs

FAQ: Why does DoNotExposeGenericLists say that I should expose Collection&lt;T&gt; instead of List&lt;T&gt;? [David Kean]

re: Why we don’t recommend using List<T> in public APIs

re: Why we don’t recommend using List<T> in public APIs

Data Access Layer 101

Data Access Layer 101

Data Access Layer 101

re: Why we don’t recommend using List&lt;T&gt; in public APIs

FAQ: Why does DoNotExposeGenericLists recommend that I expose Collection<T> instead of List<T>? [David Kean]

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

Haugerns Development Escapades » Blog Archive » .Net Collection<T> vs. List<T>

re: Why we don’t recommend using List in public APIs

Elegant Code » Replace your Collections with IEnumerable<T>

re: Why we don’t recommend using List in public APIs

The Missing .NET #2: Collection<T> AddRange() | Jason Kemp .ca

Public APIlerde List by eser.ozvataf.com

Frage zum string [] | hilpers

Supporto per estrapolare dati | hilpers

Colllection-Klasse casten | hilpers

ArrayList oder String.Concat() ? | hilpers

Lista de Generics con Eventos | hilpers

re: Why we don’t recommend using List in public APIs

re: Why we don’t recommend using List in public APIs

FAQ: Why does DoNotExposeGenericLists say that I should expose Collection<T> instead of List<T>? [David Kean]

re: Why we don’t recommend using List<T> in public APIs