webforms - ASP.NET 4.5 - unobtrusive validation, model binding, IValidatableObject interface -

i have asp.net 4.5 webforms site, , i'm trying use new fancy features model binding , unobtrusive validation.

this works quite nicely - long validate on single fields - e.g. make sure values entered etc.

but when try use ivalidatableobject interface establish validations span multiple fields, don't expected results.

imagine have myuser class generated sql server database, ef 6.1 code-first model. extend class adding partial class implements ivalidatableobject interface:

public partial class myuser : ivalidatableobject {     public ienumerable<validationresult> validate(validationcontext validationcontext) {         list<validationresult> errors = new list<validationresult>();          if(username.equals(password, stringcomparison.currentcultureignorecase))          {             errors.add(new validationresult("user name , password cannot same"));         }          return errors;     } } 

basically want check user name , password aren't same - cannot on model class itself, therefore here.

now in update (or insert, matter) method, want check if data user has entered on web form valid:

public void update(int userid) {     myuser existing = _repo.getuserbyid(userid);      if (existing == null)      {         // handle error     }      tryupdatemodel(existing);      if (modelstate.isvalid)     {        // save     } } 

i have expected validate method on partial myuser class called check if model state valid - doesn't seem happen...

what missing? how else implement cross-field validations this?

update: problems seems validate method of ivalidatableobject interface, implemented in separate partial class file, isn't recognized. ideas why??

as move method main, ef-generated myuser.cs class, works fine. great - until day need re-create entity classes database again, when database change has been made.....