FluenAPIDesign-GetMemberName_Full.cs

void Main()
{
	var p = new Person { FirstName = "Bill", LastName= "Gates", MiddleName = string.Empty, Age = 62};

	Console.WriteLine(Extensions.GetName(() => p.FirstName));
	Console.WriteLine(Extensions.GetName(() => p.LastName));
	Console.WriteLine(Extensions.GetName(() => p.Age));
	Console.WriteLine(Extensions.GetName(() => p.Birthdate));
	Console.WriteLine(Extensions.GetName(() => p.Parents));

	Console.WriteLine(Extensions.GetName(() => p.Age.ToString()));


	Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.FirstName));
	Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.LastName));
	Console.WriteLine(Extensions.EnsureNotNullOrEmpty(() => p.MiddleName));
}

// Define other methods and classes here
public class Person
{
	public string FirstName { get; set; }
	public string MiddleName { get; set; }
	public string LastName { get; set; }
	public int Age { get; set; }
	public DateTime Birthdate { get; set; }
	public List<Person> Parents { get; set; }
}

public static class Extensions
{	
	public static string GetName<T>(this Expression<Func<T>> action)
	{
		return GetNameFromMemberExpression(action.Body);
	}
	static string GetNameFromMemberExpression(Expression expression) {
		if (expression is MemberExpression) {
			return (expression as MemberExpression).Member.Name;
		}
		else if (expression is UnaryExpression) {
			return GetNameFromMemberExpression((expression as UnaryExpression).Operand);
		}
		return "MemberNameUnknown";
	}


	public static bool EnsureNotNullOrEmpty(Expression<Func<string>> member)
	{
		var memberValue = member.Compile()();
		if (string.IsNullOrEmpty(memberValue.ToString()))
		{
			throw new ArgumentException($"This property cannot be null or empty.", member.GetName());
		}
		return true;
	}
}