Represents a strongly-typed, read-only collection of elements.
Represents a strongly-typed, read-only collection of elements.
Questions tagged [readonly-collection]
105 questions
139
votes
5 answers
ReadOnlyCollection or IEnumerable for exposing member collections?
Is there any reason to expose an internal collection as a ReadOnlyCollection rather than an IEnumerable if the calling code only iterates over the collection?
class Bar
{
private ICollection foos;
// Which one is to be preferred?
…
Erik Öjebo
- 10,821
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108
votes
7 answers
Read-only list or unmodifiable list in .NET 4.0
From what I can tell, .NET 4.0 still lacks read-only lists. Why does the framework still lack this functionality? Isn't this one of the commonest pieces of functionality for domain-driven design?
One of the few advantages Java has over C# is this in…
Chris S
- 64,770
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40
votes
6 answers
How to make dictionary read-only?
I have a class like:
class A:
def __init__(self):
self.data = {}
and at some moment I want to prohibit self.data fields modification.
I've read in PEP-416 rejection notice that there are a lot of ways to do it. So I'd like to find what…
sshilovsky
- 958
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32
votes
5 answers
Why IReadOnlyCollection has ElementAt but not IndexOf
I am working with a IReadOnlyCollection of objects.
Now I'm a bit surprised, because I can use linq extension method ElementAt(). But I don't have access to IndexOf().
This to me looks a bit illogical: I can get the element at a given position, but…
Lorenzo Santoro
- 464
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30
votes
2 answers
How can I access a element of a IReadOnlyCollection through it index?
I am working with selenium and I am using the function FindElements so I am getting a element that implements IReadOnlyCollection interface. I want to iterate through the list but it seems that IReadOnlyCollection doesnt have any method like Get(int…
Yoiku
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30
votes
5 answers
How to create an empty IReadOnlyCollection
I'm creating an extension method for MultiValueDictionary to encapsulate frequent ContainsKey checks and I was wondering what was the best way to create an empty IReadOnlyCollection?.
What I've used so far is new List(0).AsReadOnly() but…
i3arnon
- 113,022
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26
votes
6 answers
What is a read only collection?
I ran a security code analyst i found myself having a CA2105 warning. I looked at the grade tampering example. I didn't realize you can assign int[] to a readonly int. I thought readonly was like the C++ const and makes it illegal.
The How to Fix…
user34537
23
votes
6 answers
ReadOnlyCollection vs Liskov - How to correctly model immutable representations of a mutable collection
Liskov-substitution principle requires that subtypes must satisfy the contracts of super-types. In my understanding, this would entail that ReadOnlyCollection violates Liskov. ICollection's contract exposes Add and Remove operations, but the…
smartcaveman
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20
votes
3 answers
Converting Dictionary> to ReadOnlyDictionary>
I have a dictionary as follows:
public enum Role { Role1, Role2, Role3, }
public enum Action { Action1, Action2, Action3, }
var dictionary = new Dictionary>();
dictionary.Add(RoleType.Role1, new Action [] { Action.Action1,…
Raheel Khan
- 14,205
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20
votes
1 answer
How to properly use IReadOnlyDictionary?
From msdn:
Represents a generic read-only collection of key/value pairs.
However consider following:
class Test
{
public IReadOnlyDictionary Dictionary { get; } = new Dictionary
{
{ "1", "111" },
…
Sinatr
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19
votes
2 answers
Entity Framework read only collections
Consider a domain where a Customer, Company, Employee, etc, etc, have a ContactInfo property which in turn contains a set of Address(es), Phone(es), Email(s), etc, etc...
Here is my abbreviated ContactInfo:
public class ContactInfo : Entity
{
…
zam6ak
- 7,229
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16
votes
1 answer
Using IReadOnlyCollection instead of IEnumerable for parameters to avoid possible multiple enumeration
My question is related to this one concerning the use of IEnumerable vs IReadOnlyCollection.
I too have always used IEnumerable to expose collections as both return types and parameters because it benefits from being both immutable and…
Neo
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15
votes
5 answers
C# HashSet read-only workaround
Here is this sample code:
static class Store
{
private static List strList = new List();
private static HashSet strHashSet = new HashSet();
public static List NormalList
{
get { return…
VBTiger
- 153
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14
votes
5 answers
Return ReadOnlyCollection from IList<>
OK, so List<> contains the AsReadOnly() which gives you the ReadOnlyCollection. What I need is to have a field of IList type, and a property which would return a ReadOnlyCollection for this list.
Example class:
class Test
{
private IList…
Denis Biondic
- 7,943
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12
votes
1 answer
Immutability/Read-only semantics (particular C# IReadOnlyCollection)
I am doubting my understanding of the System.Collection.Generic.IReadOnlyCollection semantics and doubting how to design using concepts like read-only and immutable. Let me describe the two natures I'm doubting between by using the documentation…
JBSnorro
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