Unable to cast object of type 'WhereListIterator`1[Web.Model.Appointment]' to type 'Web.Model.Appointment'

Question

This is a code fragment from my controller

[HttpPost]
public ActionResult Cancel(string id,FormCollection collection)
{
   //This is how I would like to declare appt but I cannot seem to correctly pass id into this method
   //var appt = Application.Session.GetObjectFromOid<Appointment>(new ObjectId(id));

   //I am trying to do it this way instead but I get an error
   var appt = (Appointment)Application.Appointments.Where(a=>a.Id.Equals(collection["Id"]));
   .....
}

This is the error that I get:Unable to cast object of type 'WhereListIterator`1[Web.Model.Appointment]' to type 'Web.Model.Appointment'.

This is my view:

<input type="button" value="Save" onclick="updateCancel(); return false;" /><button>Save</button>

and this is my function

 function updateCancel() {
    $('#cancel').ajaxSubmit({

    });
    }

So why am I getting this error? OR is there a way to pass Model.Data.Id into my function so that I can just use id instead?

Answer 1

The Where-clause returns an iterator. Select what you want to use instead. I.e., if you expect only one result, you can use FirstOrDefault. You can also use an index, like [1].

var appt = (Appointment)Application.Appointments.Where
     (a=>a.Id.Equals(collection["Id"]))
     .FirstOrDefault();

Note that FirstOrDefault returns null when the item is not found, so be sure to check the result value.

PS: you probably don't need your cast there. Without (Appointment, from the error in your title, this should just work, because the items in the list are of type Appointment.

Answer 2

This is what I ended up using and it worked.

var appt = Application.Session.GetObjectFromOid<Appointment>(new ObjectId(id));