Converting ObservableCollection to List?

Question

How does one convert an ObservableCollection to a List of the held objects?

Solution 1

Depending on the type of object in the ObservableCollection... I'll assume it's an int for this example:

IEnumerable<int> obsCollection = (IEnumerable<int>)GetCollection();
var list = new List<int>(obsCollection);

Solution 2

Just need to add the namespace using System.Linq;

and use the method ToList() in the ObservableCollection object

Solution 3

Given that ObservableCollection<T> implements IEnumerable<T> you can give it to the constructor of List<T>:

List<T> myList = new List<T>(myObservableCollection);

Where T is the type of the items in the collection.

Solution 4

ObservableCollection implements IList<T>, so you should be able to use ToList() on it.

http://msdn.microsoft.com/en-us/library/bb342261.aspx

Solution 5

The Items property returns an IList. See http://msdn.microsoft.com/en-us/library/ms132435.aspx

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Comments

[Matthew Scharley]

Only in 3.5 with LINQ, I'd argue just creating the list yourself from an IEnumerable is easier. This still involves a cast if you've only got an object.

[Sam Harwell]

@Matthew, I rewrote it without the unnecessary explicit cast - change it back if you don't like it this way.

[Matthew Scharley]

@280Z28: According to the original question, he's getting an object as his collection, in which case a cast is needed somewhere.

[Shawn Mclean]

why cast it to IEnumerable<>? Couldn't I just past it in the new List<>(here)?

[Matthew Scharley]

You indicated in your question that you were recieving it as an object. If you are actually recieving it as an ObservableCollection, then yes, the cast is unnecessary.

[Matthew Scharley]

That said, yes, you can do it on one line. I just dislike really long lines in code snippets here (scrolling sucks, everyone knows that).

[cdonner]

I wish I would remember this the next time I run into this very issue.