I know that calling Page.IsValid in code-behind of an ASP.NET page throws an exception if I didn't explicitly call Page.Validate before or if validation didn't happen automatically in an event handler of a control with enabled "CausesValidation".
Sometimes I am in a method or an event of a page where I need to know if all input was valid but I don't know at this particular place where the postback came from. So I don't know if the page was validated before or not, that means, if I can ask Page.IsValid without calling Page.Validate before or not.
Is there a way to check if a page was already validated (something like a boolean property "Page.HasBeenValidated" or whatever)?