How can I align the column data to center in a WPF DataGrid?
I really like Bruno's TextBlock.TextAlignment approach. You can use this in conjunction with horizontal alignment and then any background will stretch across the whole grid cell.
e.g. (in VB)
Dim sty = New System.Windows.Style(GetType(DataGridCell))
sty.Setters.Add(New Setter(HorizontalAlignmentProperty, HorizontalAlignment.Stretch))
sty.Setters.Add(New Setter(TextBlock.TextAlignmentProperty, TextAlignment.Right))
sty.Setters.Add(New Setter(BackgroundProperty, Brushes.LightGray))