如何读取WPF UserControl中传递的参数？

public partial class MyUserControl : UserControl
{
    public static readonly DependencyProperty MyParameterProperty =
        DependencyProperty.Register("MyParameter", typeof(string), typeof(MyUserControl), new PropertyMetadata(null));

    public string MyParameter
    {
        get { return (string)GetValue(MyParameterProperty); }
        set { SetValue(MyParameterProperty, value); }
    }
}

<UserControl x:Class="MyNamespace.MyUserControl"
             xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
             xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
             xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
             xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
             mc:Ignorable="d"
             d:DesignHeight="300" d:DesignWidth="300">
    <Grid>
        <TextBlock Text="{Binding MyParameter, RelativeSource={RelativeSource AncestorType=UserControl}}" />
    </Grid>
</UserControl>

        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"
        xmlns:local="clr-namespace:MyNamespace"
        mc:Ignorable="d"
        Title="MainWindow" Height="350" Width="525">
    <Grid>
       <local:MyUserControl MyParameter="{Binding MyParameter}" />
    </Grid>
</Window>