Question

In the following code I want to return an IEnumerable without creating a new data structure object. However, I get a compiler error with the following code. What am I missing?

Error       Cannot implicitly convert type 'System.Reflection.FieldInfo[]' to 'System.Reflection.FieldInfo' 

public static IEnumerable<FieldInfo> GetAllFields(Type objectType)
{
   while (objectType != null)
   {
      //GetFields(...) returns a FieldInfo []
      yield return objectType.GetFields(BindingFlags.NonPublic | BindingFlags.Public | BindingFlags.Instance | BindingFlags.DeclaredOnly);
      objectType = objectType.BaseType;
   }
}

Answer 1

Type.GetFields returns an array of FieldInfo objects.

Since you´re not returning a collection of arrays, you have to iterate over the array and yield return each object in it, kinda like this:

foreach (var fi in objectType.GetFields(...))
    yield return fi;