c# - MVC 5 not validating StringLength attribute properly -

i'm trying validate sortcode field in personpaymentdetails model view failing validate stringlength(6). if submit form value of length 1 incorrectly validates successfully.

am doing fundamentally wrong here?

/* [controller] */ public class personcontroller : controller {   [httpget]   [route("person/paymentdetails/create/{personid?}")]   public actionresult paymentdetailscreate(int? personid)   {       if (personid == null)       {           return new httpstatuscoderesult(httpstatuscode.badrequest);       }       person person = db.people.find(personid);        if (person == null)       {           return httpnotfound();       }        personpaymentdetailsviewmodel personpaymentdetailsvm = new personpaymentdetailsviewmodel();       personpaymentdetailsvm.setperson(person);        return view(personpaymentdetailsvm);   }    [httppost]   [route("person/paymentdetails/create")]   public actionresult paymentdetailscreate(personpaymentdetailsviewmodel personpaymentdetailsvm)   {       if (modelstate.isvalid)       {           /* should not entering here sortcode = 123, not 6 characters in length */           return content("no errors: |" + personpaymentdetailsvm.singlepaymentdetails.sortcode + "|");       }   } }  /* [view] */ @model x.viewmodels.personpaymentdetailsviewmodel  @html.validationsummary() @using (html.beginform("paymentdetailscreate", "person", formmethod.post, new { @class = " form-horizontal" })) {     @html.hiddenfor(m => m.person.id, "default")      <div class="form-group">         <label for="banksortcode" class="col-md-3 control-label">sort code</label>         <div class="col-md-9">             @html.editorfor(m => m.singlepaymentdetails.sortcode, new { htmlattributes = new { @class = "form-control" } })         </div>     </div>      <div class="form-group">         <label for="save" class="col-md-3 control-label">&nbsp;</label>         <div class="col-md-9">             <button type="submit" class="btn btn-primary">save</button>         </div>     </div> }  /* [model] */ public partial class personpaymentdetails {     public int id { get; set; }      [required, stringlength(6)]     public string sortcode { get; set; } }  /* [viewmodel] */ public class personpaymentdetailsviewmodel {     public person person { get; set; }     public personpaymentdetails singlepaymentdetails { get; set; }      public void setperson(person person)     {         this.person = person;         this.singlepaymentdetails = new personpaymentdetails();     } } 

you want

[required, stringlength(6, minimumlength = 6)] 

constructor of stringlength takes in maximum length only, have it checks string not longer 6 characters, , therefore string of length 1 passes validation successfully.