DataGrid cell content alignment

See more:

C#

WPF

C#4.0

Style mystyle = new System.Windows.Style();           
            Setter set = new Setter();
            set.Property = DependencyProperty.Register("TextAlignment", typeof(TextAlignment),
                typeof(Setter));
            mystyle.TargetType = typeof(TextBlock);
            set.Value = TextAlignment.Right;
            mystyle.Setters.Add(set);
           
            dataGrid1.AutoGenerateColumns = true;
            

             DataGridColumnHeader header =new DataGridColumnHeader();
             Style headerstyle = new System.Windows.Style();
            headerstyle.TargetType = header.GetType();            
            Setter setter = new Setter();
            Setter setter1 = new Setter();
            Setter setter2 = new Setter();
            setter.Property = FontSizeProperty;
            FontSize = 15;
            setter.Value = FontSize;
            headerstyle.Setters.Add(setter);
            setter1.Property = ForegroundProperty;
            Foreground = Brushes.BlueViolet;
            setter1.Value = Foreground;
            headerstyle.Setters.Add(setter1);      
            Setter setter3 = new Setter();      
            LinearGradientBrush lb = new LinearGradientBrush();
            Point startpoint=new Point(0.5,0);
            Point endpoint = new Point(1, 1);
            lb.StartPoint = startpoint;
            lb.EndPoint = endpoint;
            GradientStop gst = new GradientStop();
            lb.GradientStops.Add(new GradientStop(Colors.Yellow, 0.0));
            lb.GradientStops.Add(new GradientStop(Colors.Orange, 0.5));
            lb.GradientStops.Add(new GradientStop(Colors.Red, 1.0));           
            setter3.Property = BackgroundProperty;
            setter3.Value = lb;
            headerstyle.Setters.Add(setter3);
            headerstyle.Setters.Add(set);
          dataGrid1.HeaderStyle = headerstyle;

in this code for the column header the defined styles are taking place but regarding the code segment

Style mystyle = new System.Windows.Style();           
            Setter set = new Setter();
            set.Property = DependencyProperty.Register("TextAlignment", typeof(TextAlignment),
                typeof(Setter));
            mystyle.TargetType = typeof(TextBlock);
            set.Value = TextAlignment.Right;
            mystyle.Setters.Add(set);
            headerstyle.Setters.Add(set);         

it seems that it do not have any action. in fact I want the header content and cell content aligned in center. how I can approach this using codebehind.