c# - Why is the model binder mixing up ID fields? -

i have model used add new address, in view shopid in hiddenfor , id 0, fk shop null there no id set in it.

public int id { get; set; } public string shopid { get; set; } public string addressline1 { get; set; } public string addressline2 { get; set; } public string addressline3 { get; set; } public string district { get; set; } public string region { get; set; } public string postalcode { get; set; } public int countryid { get; set; } public system.datetime creationtimestamp { get; set; } public bool isprimary { get; set; } public nullable<double> latitude { get; set; } public nullable<double> longitude { get; set; }  public virtual country country { get; set; } public virtual shop shop{ get; set; } 

when post form modelstate.isvalid showing false saying value in shopid invalid in id field:

the value 'd04bf59f-be29-4896-ae70-54432b02aa46' not valid id.

why model binding placing shopid id field?

here's view:

@using (html.beginform()) {     @html.antiforgerytoken()      <div class="form-horizontal">         <h4>shopaddress</h4>         <hr />         @html.validationsummary(true)         @html.hiddenfor(m => model.shopid)         <div class="form-group">             @html.labelfor(model => model.addressline1, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.addressline1, new { @class = "form-control" })                 @html.validationmessagefor(model => model.addressline1)             </div>         </div>          <div class="form-group">             @html.labelfor(model => model.addressline2, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.addressline2, new { @class = "form-control" })                 @html.validationmessagefor(model => model.addressline2)             </div>         </div>          <div class="form-group">             @html.labelfor(model => model.addressline3, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.addressline3, new { @class = "form-control" })                 @html.validationmessagefor(model => model.addressline3)             </div>         </div>          <div class="form-group">             @html.labelfor(model => model.district, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.district, new { @class = "form-control" })                 @html.validationmessagefor(model => model.district)             </div>         </div>         <div class="form-group">             @html.labelfor(model => model.region, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.region, new { @class = "form-control" })                     @html.validationmessagefor(model => model.region)             </div>         </div>         <div class="form-group">             @html.labelfor(model => model.postalcode, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.textboxfor(model => model.postalcode, new { @class = "form-control" })                 @html.validationmessagefor(model => model.postalcode)             </div>         </div>         <div class="form-group">             @html.labelfor(model => model.country, "country", new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.dropdownlistfor(model => model.countryid, (ienumerable<selectlistitem>)viewbag.countries, new { @class = "form-control" })                 @html.validationmessagefor(model => model.country)             </div>         </div>         <div class="form-group">             @html.labelfor(model => model.isprimary, new { @class = "control-label col-md-2" })             <div class="col-md-10">                 @html.radiobuttonfor(model => model.isprimary, "true") yes                 @html.radiobuttonfor(model => model.isprimary, "false") no             </div>         </div>          <div class="form-group">             <div class="col-md-offset-2 col-md-10">                 <input type="submit" value="create" class="btn btn-default" />             </div>         </div>     </div> } 

most binder tries best find value id, , since it's not presented in view, take field has 'id" in it's name. try add hidden field id or create model view instead of passing domain object