Question

Having a strange issue with some C# code – the Getter method for a property is showing up as virtual when not explicitly marked.

The problem exhibits with the DbKey property on this class (code in full):

public class ProcessingContextKey : BusinessEntityKey, IProcessingContextKey {     public ProcessingContextKey()     {         // Nothing     }      public ProcessingContextKey(int dbKey)     {         this.mDbKey = dbKey;     }      public int DbKey     {         get { return this.mDbKey; }         set { this.mDbKey = value; }     }     private int mDbKey;      public override Type GetEntityType()     {         return typeof(IProcessingContextEntity);     } } 

When I use reflection to inspect the DbKey property, I get the following (unexpected) result:

Type t = typeof(ProcessingContextKey); PropertyInfo p = t.GetProperty('DbKey'); bool virtualGetter = p.GetGetMethod(true).IsVirtual; // True! bool virtualSetter = p.GetSetMethod(true).IsVirtual; // False 

Why does virtualGetter get set to True? I expected false, given that the property is neither abstract nor virtual.

For completeness – and for the remote possibilty they are relevant, here are the declarations for BusinessEntityKey, IProcessingContextKey, and IBusinessEntityKey:

public abstract class BusinessEntityKey : IBusinessEntityKey {     public abstract Type GetEntityType(); }  public interface IProcessingContextKey : IBusinessEntityKey  {     int DbKey { get; } }  public interface IBusinessEntityKey {     Type GetEntityType(); } 

Thanks in advance for your help.

Clarification – why does this matter to me?

We’re using NHibernate and traced some issues with lazy loading to properties that were only half overridable – virtual getter but private setter. After fixing these up, we added a Unit test to catch any other places where this could occur:

public void RequirePropertiesToBeCompletelyVirtualOrNot() {     var properties         = typeof(FsisBusinessEntity).Assembly             .GetExportedTypes()             .Where(type => type.IsClass)             .SelectMany(                 type =>                      type.GetProperties(                         BindingFlags.Instance                          | BindingFlags.Public                          | BindingFlags.NonPublic))             .Where(property => property.CanRead                  && property.CanWrite)             .Where(property =>                  property.GetGetMethod(true).IsVirtual                      != property.GetSetMethod(true).IsVirtual);      Assert.That(         properties.Count(),         Is.EqualTo(0),         properties.Aggregate(             'Found : ',              (m, p) => m + string.Format('{0}.{1}; ',                      p.DeclaringType.Name,                      p.Name))); } 

This unit test was failing on the DbKey property mentioned above, and I didn’t understand why.

Answer 1

It’s virtual because it implements an interface method. Interface implementation methods are always virtual as far as the CLR is concerned.