I'm not sure why you have One.Value, Two.Value, Three.Value in your bindings. I think you meant Id.Value, Title.Value and Body.Value, correct?
I think the only way you can do this is with a converter. Here is one way of doing it:
<DataTrigger Binding="{Binding RelativeSource={RelativeSource Self}, Converter={StaticResource UpdatedConverter}}" Value="True">
<Setter Property="Background" Value="Green" />
</DataTrigger>
And the converter:
public class UpdatedConverter : IValueConverter
{
#region IValueConverter Members
public object Convert(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
DataGridCell dgc = value as DataGridCell;
if (dgc != null)
{
Issue data = dgc.DataContext as Issue;
if (data != null)
{
DataGridTextColumn t = dgc.Column as DataGridTextColumn;
if (t != null)
{
var binding = t.Binding as System.Windows.Data.Binding;
if (binding != null && binding.Path != null && binding.Path.Path != null)
{
string val = binding.Path.Path.ToLower();
if (val.StartsWith("id"))
return data.Id.Updated;
if (val.StartsWith("title"))
return data.Title.Updated;
if (val.StartsWith("body"))
return data.Body.Updated;
}
}
}
}
return false;
}
public object ConvertBack(object value, Type targetType, object parameter, System.Globalization.CultureInfo culture)
{
throw new NotImplementedException();
}
#endregion
}