How to Get Enum By Description Values?

Question

I have an enum width descriptions:

  public enum PostTypes {

    [Description("Business")]
    Business = 1 << 0,

    [Description("Design"]
    Design = 1 << 1,

    [Description("Marketing")]
    Marketing = 1 << 2,

  } // PostTypes

I would like to get an Enum based on Description, so:

1 - If I have String="Business" I would get PostTypes.Business.

2 - If I have String[] = new String[] { "Business", "Design" } I would have PostTypes.Business | PostTypes.Design.

UPDATE

I am using the following:

Enum.GetValues(typeof(PostTypes)).Cast<PostTypes>().Where(v => new String[] { "Business", "Design" }.Contains(v.GetDescription())).Aggregate((a, b) => a | b);

This is working even for Flag enums and string arrays.

Could someone, please, help me in creating an extension where I pass the enum type and use a func for setting the rule for search, either the Description attribute or any other.

How can I do this?

Thank You, Miguel