Adding an item to IEnumerable

Question

I had a List<> of my objects, but now need to change it to an IEnumerable<>. So, I have this:

public IEnumerable<TransactionSplitLine> TransactionSplitLines { get; set; }

However, I can no longer do:

reply.TransactionSplitLines.Add(new TransactionSplitLine
                                                    {Amount = "100", Category = "Test", SubCategory = "Test More", CategoryId=int.Parse(c)});

How should I be adding items now?

Answer 1

You could do something like the following, using Concat:

reply.TransactionSplitLines = 
    reply.TransactionSplitLines.Concat(new []{new TransactionSplitLine                                                     {
                                                 Amount = "100", 
                                                 Category = "Test", 
                                                 SubCategory = "Test More",
                                                 CategoryId = int.Parse(c)}});

That basically creates a new IEnumerable. It's hard to say what's the best solution in your case, since there are not enough information about your use case.

EDIT: Please note that List<T> implements IEnumerable<T>. So if you need to pass an IEnumerable<T> as a parameter for example, you can also pass a List<T> instead, maybe calling explicitly AsEnumerable() on your list first. So maybe you could stick with a List instead of an IEnumerable.