Initialize IList<T> C#

Question

Is there a particular way to initialize an IList<T>? This does not seem to work:

IList<ListItem> allFaqs = new IList<ListItem>(); // Error I get here: Cannot create an instance of the interface 'IList<ListItem>' 

ReSharper suggests to initialize it like so:

IList<ListItem> allFaqs = null; 

But won't that cause a Null Reference Exception when I go to add items to this list?

Or should I just use List<ListItem>?

Thanks!

Answer 1

The error is because you're trying to create an instance of the interface.

Change your code to:

List<ListItem> allFaqs = new List<ListItem>(); 

or

IList<ListItem> allFaqs = new List<ListItem>(); 

and it should compile.

You'll obviously have to change the rest of your code to suit too.

You can create any concrete type that implements IList like this, so

IList<ListItem> test = new ListItem[5];  IList<ListItem> test = new ObservableCollection<ListItem>(allFaqs); 

and so on, will all work.