Question

I am using an interface I found, which has a method that takes a LINQ expression as a parameter.
How would I implement this method to use the LINQ Expression? I can see it being very useful, but dont how to write the code to use it!!

Its a repository interface.

signature is…

IQueryable<T> Get(Expression<Func<T, bool>> criteria);

Answer 1

Sounds like you are looking for something like this:

List<T> myList = new List<T>();
...
public IQueryable<int> Get(Expression<Func<int, bool>> criteria)
{
    return myList.Where(criteria.Compile()).AsQueryable();
}

This passes your expression criteria to the linq-method Where. You can then call it like this:

foreach(var something in myClass.Get(o => o.someProperty == 10))
{
    ...
}

Of course, this is pretty stupid; it would be better to just implement IEnumerable<T>…