Why doesn't HorizontalContentAlignment work in Silverlight as it does in WPF?

Question

In WPF, tb.HorizontalContentAlignment = HorizontalAlignment.Center works:

WPF XAML:

<Window x:Class="TestText2343434.Window1"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    Title="Window1" Height="300" Width="300">
    <Grid>
        <StackPanel x:Name="MainContent" Margin="10" HorizontalAlignment="Left"/>
    </Grid>
</Window>

WPF Code Behind:

using System.Windows;
using System.Windows.Controls;

namespace TestText2343434
{
    public partial class Window1 : Window
    {
        public Window1()
        {
            InitializeComponent();

            TextBox tb = new TextBox();
            tb.Width = 30;
            tb.MaxLength = 1;
            tb.HorizontalContentAlignment = HorizontalAlignment.Center;

            MainContent.Children.Add(tb);
        }
    }
}

In Silverlight, tb.HorizontalContentAlignment = HorizontalAlignment.Center does not work:

Silverlight XAML:

<UserControl x:Class="TestContent222.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation" 
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008" xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006" 
    mc:Ignorable="d" d:DesignWidth="640" d:DesignHeight="480">
  <Grid x:Name="LayoutRoot">
        <StackPanel x:Name="MainContent" Margin="10" HorizontalAlignment="Left"/>
  </Grid>
</UserControl>

Silverlight Code Behind:

using System.Windows;
using System.Windows.Controls;

namespace TestContent222
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();

            TextBox tb = new TextBox();
            tb.Width = 30;
            tb.MaxLength = 1;
            tb.HorizontalContentAlignment = HorizontalAlignment.Center;

            MainContent.Children.Add(tb);
        }
    }
}

What do I have to do to make HorizontalContentAlignment work in Silverlight as it does in WPF?

Answer 1

HorizontalContentAlignment is not a valid property on a TextBox in Silverlight (it is not exposed in Expression Blend or the VS2010 properties window).

You want to set the equivalent of TextAlignment="Center" which is

tb.TextAlignment = System.Windows.TextAlignment.Center;

Hope this helps.