C# 4 and .NET 4

1068 ❘ ChaPTer 36 business ApplicAtiOns with wpf
through pages. In a simple scenario, only the ItemsSource property of the DataGrid needs to be assigned.
By default, the DataGrid creates columns based on the properties of the bound data:
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code snippet Formula1Demo/GridUC.xaml
The code-behind uses the same Formula1 database as the previous TreeView example. The DataContext of
the UserControl is set to the Races property. This property returns IEnumerable.
Instead of assigning a strongly typed enumeration, an object is used to make it possible to create an
anonymous class with the LINQ query. The LINQ query creates the anonymous class with Year, Country,
Position, Racer, and Car properties and uses a compound to access Races and RaceResults. It also
accesses other associations of Races to get country, racer, and team information. With the Skip() and
Take() methods, paging functionality is implemented. The size of a page is fixed to 50 items, and the
current page changes with the OnNext() and OnPrevious() handlers:
using System.Collections.Generic;
using System.Linq;
using System.Windows;
using System.Windows.Controls;
namespace Formula1Demo
{
public partial class GridUC : UserControl
{
private int currentPage = 0;
private int pageSize = 50;
private Formula1Entities data = new Formula1Entities();
public GridUC()
{
InitializeComponent();
this.DataContext = Races;
}
public IEnumerable Races
{
get
{
return (from r in data.Races
from rr in r.RaceResults
orderby r.Date ascending
select new
{
Year = r.Date.Year,
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