public class SaleViewModel : INotifyPropertyChanged
{
    private ObservableCollection<Sale> _sales = new ObservableCollection<Sale>();
 
    public SaleViewModel()
    {
        //データを読み込みます
        LoadData();
    }
 
    public ObservableCollection<Sale> Sales
    {
        get { return _sales; }
    }
 
    public void LoadData()
    {
        //TODO：データソースからデータを読み込みます
        _sales.Add(new Sale("Bikes", 23812.89, 12479.44));
        _sales.Add(new Sale("Shirts", 79752.21, 19856.86));
        _sales.Add(new Sale("Helmets", 63792.05, 16402.94));
        _sales.Add(new Sale("Pads", 30027.79, 10495.43));
    }
 
    public event PropertyChangedEventHandler PropertyChanged;
 
    void OnPropertyChanged(string propertyName)
    {
        if (PropertyChanged != null)
            PropertyChanged(this, new PropertyChangedEventArgs(propertyName));
    }
}