Validation of Guid

Question

I have a strongly-typed view which has a DropDownListFor attribute on it.

Each item in the dropdown list is represented by a GUID.

What I\'m after is a way

Answer 1

You can validate the Guid if it contains default values - "00000000-0000-0000-0000-000000000000".

  if (model.Id == Guid.Empty)
  {
           // TODO: handle the error or do something else
  }

Answer 2

Bad answer. See below...

Using a regex to block empty / default Guid worked for me. Use in combination with 'Required'. I.e.

    [Required]
    [RegularExpression("^(?!(00000000-0000-0000-0000-000000000000)$)", ErrorMessage = "Cannot use default Guid")]
    public Guid Id { get; set; }

EDIT: Actually this doesn't work. It rejects everything. I'll leave this answer so others don't bother trying it.