What's wrong with this reflection code? GetFields() is returning an empty array

Chris McCall picture Chris McCall · Jun 24, 2009 · Viewed 24.8k times · Source

C#, Net 2.0

Here's the code (I took out all my domain-specific stuff, and it still returns an empty array):

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

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            ChildClass cc = new ChildClass();
            cc.OtherProperty = 1;

            FieldInfo[] fi = cc.GetType().GetFields();
            Console.WriteLine(fi.Length);
            Console.ReadLine();
        }
    }
    class BaseClass<T>
    {
        private int myVar;

        public int MyProperty
        {
            get { return myVar; }
            set { myVar = value; }
        }


    }

    class ChildClass : BaseClass<ChildClass>
    {
        private int myVar;

        public int OtherProperty
        {
            get { return myVar; }
            set { myVar = value; }
        }

    }
}

Answer

Jon Skeet picture Jon Skeet · Jun 24, 2009

The parameterless GetFields() returns public fields. If you want non-public ones, use:

cc.GetType().GetFields(BindingFlags.Instance | BindingFlags.NonPublic);

or whatever appropriate combination you want - but you do need to specify at least one of Instance and Static, otherwise it won't find either. You can specify both, and indeed public fields as well, to get everything:

cc.GetType().GetFields(BindingFlags.Instance | 
                       BindingFlags.Static |
                       BindingFlags.NonPublic |
                       BindingFlags.Public);