Question

Through reflection, is there some way for me to look at a generic List’s contained type to see what type the collection is of? For example:

I have a simple set of business objects that derive from an interface, like this:

public interface IEntityBase{}    public class BusinessEntity : IEntityBase    {     public IList<string> SomeStrings {get; set;}            public IList<ChildBusinessEntity> ChildEntities { get; set;} }   public class ChildBusinessEntity : IEntityBase{} 

In the case where I am iterating through the properties of BusinessEntity through reflection, would there be a way for me to see if the objects nested inside those lists derived from IEntityBase?

Pseudocoded (badly) like this:

foreach(PropertyInfo info in typeof(BusinessEntity).GetProperties()) {   if(info.PropertyType is GenericIList &&      TheNestedTypeInThisList.IsAssignableFrom(IEntityBase)   {     return true;   } } 

Only option I’ve heard so far, that works, would be to pull out the first item from that list, then look at its type. Any easier way (especially because I can’t be guaranteed that the List won’t be empty)?

Answer 1

Assuming you have the System.Type which describes your List<>, you can use the Type.GetGenericArguments() method to get the Type instance which describes what it’s a list of.