Question

I’m doing some dynamic code generation using Reflection, and I’ve come across a situation where I need to get the backing field of a property (if it has one) in order to use its FieldInfo object.

Now, I know you can use

.IsDefined(typeof(CompilerGeneratedAttribute), false);

on a FieldInfo to discover whether it’s autogenerated, so I assume there’s a similar thing for Properties which auto-generate fields?

Cheers, Ed

Answer 1

The get_ and set_ methods for properties also get the CompilerGeneratedAttributed applied to them. While there is no strong coupling through attributes, there is a naming convention used for the backing fields of an auto property:

public string Foo { get; set;}

Produces a private string <Foo>k__BackingField member (the < and > here are part of the name, as they’re legal in IL but not in C#; they have nothing to do with generics).

As an example, this will get a list of all of the auto properties in a class, along with their backing fields:

t.GetProperties().Where(p => 
    (p.GetGetMethod() ?? p.GetSetMethod()).IsDefined(typeof(CompilerGeneratedAttribute), false))
   .Select(p => new 
   { 
      Property = p, 
      Field = t.GetField(string.Format("<{0}>k__BackingField", p.Name),
          System.Reflection.BindingFlags.NonPublic | 
          System.Reflection.BindingFlags.Instance) 
   });