title: Why does the DataGrid not update when the ItemsSource is changed?
body: <p>I have a datagrid in my wpf application and I have a simple problem. I have a generic list and I want to bind this collection to my datagrid data source every time an object is being added to the collection. and I'm not interested to use observable collection.</p>
  
  <p>the point is I'm using the same method somewhere else and that works fine. but this time when i press Add button an object is added and datagrid updates correctly but from the second item added to collection datagrid does not update anymore.</p>
  
  <p>Here is the Code :</p>
  
  <pre><code> private void btnAddItem_Click(object sender, RoutedEventArgs e)
      {
          OrderDetailObjects.Add(new OrderDetailObject
          {
              Price = currentitem.Price.Value,
              Quantity = int.Parse(txtQuantity.Text),
              Title = currentitem.DisplayName,
              TotalPrice = currentitem.Price.Value * int.Parse(txtQuantity.Text)
          });
  
          dgOrderDetail.ItemsSource = OrderDetailObjects;
          dgOrderDetail.UpdateLayout();
      }
  </code></pre>
  
  <p>any idea ?</p>