1，先在Silverlight项目中新建一个接口文件IContent.cs，内容如下：

using System.Windows;namespace BookStore {    public interface IContent     {        UIElement Content        { get; set; }    }}

　　2，建立两个xaml文件：Second.xaml和SilverlightControl1.xaml

SilverlightControl1.xaml的完整内容如下：

using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using BookStore;namespace SilverlightApplication1{    public partial class SilverlightControl1 : UserControl,IContent    {        public SilverlightControl1()        {            InitializeComponent();        }        public new UIElement Content         {            get { return base.Content; }            set { base.Content = value; }        }        private void BtnFirst_Click(object sender,EventArgs e)        {            (Application.Current.RootVisual as IContent).Content = new Second();        }    }}

Second.xaml完整内容如下：

using System;using System.Collections.Generic;using System.Linq;using System.Net;using System.Windows;using System.Windows.Controls;using System.Windows.Documents;using System.Windows.Input;using System.Windows.Media;using System.Windows.Media.Animation;using System.Windows.Shapes;using BookStore;namespace SilverlightApplication1{    public partial class Second : UserControl,IContent    {        public Second()        {            InitializeComponent();        }        public new UIElement Content         {            get { return base.Content; }            set { base.Content = value; }        }        private void BtnSecond_Click(object sender,EventArgs e)        {            (Application.Current.RootVisual as IContent).Content = new SilverlightControl1();        }    }}