Data Annotation/Validation and dynamic values

If some of my models have dynamic validation conditions (i.e. the string length can be minimum of 8 or 12 depending on a database value or so开发者_StackOverflow中文版me other dynamic value) is it impossible to use data annotation for validation?

From what I understand, the values of any parameter (example StringLength min/max value) have to be truly static. Are there alternatives for applications that have dynamic validation values?

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Your pretty much stuck with writing your own custom validationattribute:

http://msdn.microsoft.com/en-us/library/system.componentmodel.dataannotations.validationattribute.aspx