When in doubt, follow MVC conventions.
Create a viewModel if you haven't already that contains a property for JobID
public class Model
{
public string JobId {get; set;}
public IEnumerable<MyCurrentModel> myCurrentModel { get; set; }
//...any other properties you may need
}
Strongly type your view
@model Fully.Qualified.Path.To.Model
Add a hidden field for JobId to the form
using (@Html.BeginForm("myMethod", "Home", FormMethod.Post))
{
//...
@Html.HiddenFor(m => m.JobId)
}
And accept the model as the parameter in your controller action:
[HttpPost]
public FileStreamResult myMethod(Model model)
{
sting str = model.JobId;
}