Today a coworker of mine needed to know how he could check a property of a certain class implemented a certain interface. In this case it was the System.Collections.IEnumerable interface. The following code is a custom class to demonstrate that it’s property implements the interface System.Collections.IEnumerable.

using System;
using System.Collections.Generic;
using System.Text;

namespace InterfaceCheck {
	public class ClassToCheck {
		private List stringsProperty;
 		public List StringsProperty {
			get { return stringsProperty; }
			set { stringsProperty = value;
}
}
}

The property is of type System.Collections.Generics.List<String>. If everything is correct this property will return that it implements the IEnumerable interface because the List<T> implements it. The following code is checking it:

ClassToCheck ctc = new ClassToCheck();

foreach (PropertyInfo propertyInfo in ctc.GetType().GetProperties())
{
	if (propertyInfo.PropertyType.GetInterface("System.Collections.IEnumerable")
	 != null)
Console.WriteLine("Interface is implemented");
	else 	
	Console.WriteLine("Interface not implemented");
}

It's following piece of code that does the checking: if (propertyInfo.PropertyType.GetInterface( "System.Collections.IEnumerable") != null) If the property implements the IEnumerable interface it will return it, if not it will return null.