title: Reports VS 2010, drill down ICollection
body: <p>I have the following Linq, its linked to a report. </p>
  
  <p>Resuming it's a report of bills, but bills have multiple products, so i have an <code>ICollection</code> of <code>Products</code>. The idea is to show each bill with their multiple <code>Products</code> in a single report using drilldown (trying to avoid subreports).</p>
  
  <pre><code>public class BillsDataSet
  {
      public int IDGestion { get; set; }
      public string Comentario { get; set; }
      public ICollection&lt;BillProduct&gt; Products { get; set; }
      public decimal Monto { get; set; }
      public string Personal { get; set; }
  
      public static List&lt;BillsDataSet&gt; BillsPorFecha(DateTime dtFechaInicial, DateTime dtFechaFinal)
      {
          Context db = new Context();
  
          List&lt;BillsDataSet&gt; BillsDataSet = (from p in db.Bill
                                                 select new BillsDataSet()
                                                 {
                                                     IDGestion = p.IDBill,
                                                     Comentario = p.Historial.FirstOrDefault().Comentario,
                                                     Products = p.BillProduct,
                                                     Monto = p.Total,
                                                     Personal = p.Historial.FirstOrDefault().CodigoEmpleado
                                                 }).ToList();
          return BillsDataSet;
      }
  }
  </code></pre>
  
  <p>I'm getting this error on the web page report...
  <img src="https://i.stack.imgur.com/02QeF.png" alt="I&#39;m getting this error on the web page report"></p>
  
  <p>What I want to achieve is to have a drilldown on <code>Products</code> to hide/show all the <code>Products</code> related to the bill...</p>