CompareAttribute validator?

Validation attributes are realy nice. But what if I have to compare one proper开发者_运维问答ty to another. How can I implement that?

Scott has a great example for Email attribute validator at http://weblogs.asp.net/scottgu/archive/2010/01/15/asp-net-mvc-2-model-validation.aspx but it's bind to only one property.

What if I need to compare one date to another (DateFrom, DateTo), so that DateFrom is before DateTo?

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Check out this SO answer.