Question

I’m using the following code to retrieve named members from an anonymous type. Is there some way I could convert the follwing code to use a lambda expression to achieve this, or at least to allow the calling code to use a lamda, even if ‘deep down’ I have to use a string?

private T GetAnonymousTypeMember<T>(object anonymousType, string memberName) where T: class 
{
  var anonTypesType = anonymousType.GetType();
  var propInfo = anonTypesType.GetProperty(memberName);
  return propInfo.GetValue(anonymousType, null) as T;
}

ADDED:
This is how anonymousType arrives. The GetAnonymousTypeMember method is private to a class whose only public method is declared as follows:

public void PublishNotification(NotificationTriggers trigger, object templateParameters)

I call this method:

PublishNotification(NotificationTriggers.RequestCreated, new {NewJobCard = model});

That new {NewJobCard = model} is what is passed to GetAnonymousTypeMember as anonymousType.

Answer 1

public U GetMemberValue<T, U>(T instance, Expression<Func<T, U>> selector)
{
    Type type = typeof(T);
    var expr = selector.Body as MemberExpression;
    string name = expr.Member.Name;

    var prop = type.GetProperty(name);
    return (U)prop.GetValue(instance, null);
}

Will enable to to do:

string name = GetMemberValue(new { Name = "Hello" }, o => o.Name);