Question

Given the following class definitions:

public class BaseClass {     public string SomeProp1 { get; set; } }  public class DerivedClass : BaseClass {     public string SomeProp2 { get; set; } } 

How can I take a List<BaseClass> and convert it to a List<DerivedClass>?

In my real-world scenario BaseClass has a whole bunch of properties that I don’t want to have to copy over one-by-one (and then remember to maintain if an additional property gets added).

Adding a parameterised constructor to BaseClass is not an option as this class is defined by a WCF service reference.

Answer 1

List<DerivedClass> result =      listBaseClass.ConvertAll(instance => (DerivedClass)instance); 

Actually ConvertAll is good when you need to create new objects based on the original, when you just need to cast you can use the following

List<DerivedClass> result =      listBaseClass.Cast<DerivedClass>().ToList(); 

If not all of the items in your list can be cast to DerivedClass then use OfType instead

List<DerivedClass> result =     listBaseClass.OfType<DerivedClass>().ToList();