How can I cast a list to an observablecollection in c#?

Question

I have a List that I want to cast to an ObservableCollection, this is my code

var list = Models.Lands.FromJson(responce.Result.ToString());
this.Lands = new ObservableCollection<Land>( list );

FromJson returns me a List<Models.Land>, and this.Lands is an ObservableCollection<Models.Land>.

new ObservableCollection<Models.Land>( list ) gives me the following error:

cannot convert from System.Collections.Generic.List<> to System.Collections.Generic.IEnumerable<>,

I thought that the constructor was overloaded for a List<> object.

What are they types given in your error? A `List` can be converted to an `IEnumerable` so presumably your generic objects are of different types but you seem to have stripped out this crucial information... — Chris, Jun 22 '18 at 14:07
Possible duplicate of [How to convert IEnumerable to ObservableCollection?](https://stackoverflow.com/questions/3559821/how-to-convert-ienumerable-to-observablecollection) — d.moncada, Jun 22 '18 at 14:19

Jose Agustin Reinoso · Answer 1 · 2018-06-22T14:03:53.070

0

Try using the nongeneric var keyword.

List<Land> list =Models.Lands.FromJson(responce.Result.ToString());
var collection = new ObservableCollection<Land>(list);

edited Jun 22 '18 at 14:03

answered Jun 22 '18 at 13:54

Jose Agustin Reinoso

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Legion · Answer 2 · 2018-06-22T14:44:36.110

0

I think you can do something like below to avoid your problem but still using a single line of code:

this.Lands = new ObservableCollection<Land>( list.ToArray<Land>());

but I'm not sure if that's an efficient way to do that.

edited Jun 22 '18 at 14:44

answered Jun 22 '18 at 14:37

Legion

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Why ToArray? The ObservableCollection constructor takes an IEnumerable so there is no need to copy all list elements to an array which is then copied to the ObservableCollection. – ckuri Jun 22 '18 at 16:40
I agree with you, but i encounter the same error times ago and without the "toArray" you got the error, with it the error disappear... The difference is that in Observable collection you're casting a Lands[] instead of List, but i agree that both should be converted into IEnumerable without any problem. – Legion Jun 28 '18 at 14:43

score -1 · Answer 3 · answered Jun 22 '18 at 13:54

Works in my browser: https://dotnetfiddle.net/VVB8YY

public static void Main()
{
    var list = new List<String>{"a", "b", "c"};
    var collection = new ObservableCollection<string>(list);

    foreach (var value in collection)
    {
        Console.WriteLine(value);
    }

    Console.WriteLine("Hello World");
}

How can I cast a list to an observablecollection in c#?

3 Answers3