readonly-collection

I have this example code. What I want to do is to make it so that the "Nums" value can only be written to using the "AddNum" method. namespace ConsoleApplication1 { public class Person { string myName = "N/A"; int myAge = 0; List<int> _nums = new List<int>(); public List<int> Nums { get { return _nums; } } public void AddNum(int NumToAdd) { _nums.Add(NumToAdd); } public string Name { get; set; } public int Age { get; set; } } } Somehow, I've tried a bunch of things regarding AsReadOnly() and the readonly keyword, but I can't seem to get it to do what I want it to do. Here is the sample of the

Liskov-substitution principle requires that subtypes must satisfy the contracts of super-types. In my understanding, this would entail that ReadOnlyCollection<T> violates Liskov. ICollection<T> 's contract exposes Add and Remove operations, but the read only subtype does not satisfy this contract. For example, IList<object> collection = new List<object>(); collection = new System.Collections.ObjectModel.ReadOnlyCollection<object>(collection); collection.Add(new object()); -- not supported exception There is clearly a need for immutable collections. Is there something broken about .NET's way of

From msdn : Represents a generic read-only collection of key/value pairs. However consider following: class Test { public IReadOnlyDictionary<string, string> Dictionary { get; } = new Dictionary<string, string> { { "1", "111" }, { "2", "222" }, { "3", "333" }, }; public IReadOnlyList<string> List { get; } = (new List<string> { "1", "2", "3" }).AsReadOnly(); } class Program { static void Main(string[] args) { var test = new Test(); var dictionary = (Dictionary<string, string>)test.Dictionary; // possible dictionary.Add("4", "444"); // possible dictionary.Remove("3"); // possible var list =

Is there a c# language construct that will allow me to add items to a readonly collection property in a constructor? I want to do something like this: public class Node{ public IList<Node> Children {get; protected set;} public Node(){ Children = new ObservableList<Node>(); } } ... in my code somewhere... var node = new Node {Children.Add(new Node())}; (not a great example, but I hope this gets the idea across)... UPDATE OK sorry I need to be clearer. I didn't write this Node class, and I cannot change it. I am asking if there is a c# language concept that will allow me to add to the readonly

My question is related to this one concerning the use of IEnumerable<T> vs IReadOnlyCollection<T> . I too have always used IEnumerable<T> to expose collections as both return types and parameters because it benefits from being both immutable and lazily executed. However, I am becoming increasingly concerned about the proliferation of places in my code where I must enumerate a parameter to avoid the possible multiple enumeration warning that ReSharper gives. I understand why ReSharper suggests this, and I agree with the code it suggests (below) in order to ensure encapsulation (i.e., no