Polymorphic Enums for state handling

Question

how do i handle Enums without using switch or if statements in C#?

For Example

enum Pricemethod
{
    Max,
    Min,
    Average
}

... a

Answer 1

how do I handle enums without using switch or if statements in C#?

You don't. enums are just a pleasant syntax for writing const int.

Consider this pattern:

public abstract class PriceMethod
{
  // Prevent inheritance from outside.
  private PriceMethod() {}

  public abstract decimal Invoke(IEnumerable sequence);

  public static PriceMethod Max = new MaxMethod();

  private sealed class MaxMethod : PriceMethod
  {
    public override decimal Invoke(IEnumerable sequence)
    {
      return sequence.Max();
    }
  }

  // etc, 
}

And now you can say

public decimal Price
{
    get { return PriceMethod.Invoke(this.PriceHistory); }
}

And the user can say

myArticle.PriceMethod = PriceMethod.Max;
decimal price = myArticle.Price;