Add elements from IList to ObservableCollection

Question

I have an ObservableCollection, and I'd like to set the content of an IList to this one. Now I could just create a new instance of the collection..:

public ObservableCollection<Bar> obs = new ObservableCollection<Bar>(); 
public void Foo(IList<Bar> list)
{
    obs = new ObservableCollection<Bar>(list); 
}

But how can I actually take the content of the IList and add it to my existing ObservableCollection? Do I have to loop over all elements, or is there a better way?

public void Foo(IList<Bar> list)
{
   foreach (var elm in list)
       obs.Add(elm); 
}

Answer 1

Looping is the only way, since there is no AddRange equivalent for ObservableCollection.

Answer 2

You could write your own extension method if you are using C#3+ to help you with that (I haven't tested the code below, so there might be some errors, but you should get the idea):

public void AddRange<T>(this ObservableCollection<T> coll, IEnumerable<T> items)
{
    foreach (var item in items)
    {
        coll.Add(item);
    }
}

Answer 3

You could do

public void Foo(IList<Bar> list)
{
    list.ToList().ForEach(obs.Add);
}

or as an extension method,

    public static void AddRange<T>(this ObservableCollection<T> collection, IEnumerable<T> items)
    {
        items.ToList().ForEach(collection.Add);
    }