文通过改变DataContext，让ListBox的Item绑定到不同的ObservableCollection。

首先，我们在页面上放一个ListBox，它的ItemsSource绑定设置为strs，
在页面上把一个Button，通过点击这个Button更改DataContext，
xaml代码如下：

Code:
<phone:PhoneApplicationPage 
    x:Class="HelloWP7.MainPage"
    xmlns="http://schemas.microsoft.com/winfx/2006/xaml/presentation"
    xmlns:x="http://schemas.microsoft.com/winfx/2006/xaml"
    xmlns:phone="clr-namespace:Microsoft.Phone.Controls;assembly=Microsoft.Phone"
    xmlns:shell="clr-namespace:Microsoft.Phone.Shell;assembly=Microsoft.Phone"
    xmlns:d="http://schemas.microsoft.com/expression/blend/2008"
    xmlns:mc="http://schemas.openxmlformats.org/markup-compatibility/2006"
    mc:Ignorable="d" d:DesignWidth="480" d:DesignHeight="768"
    FontFamily="{StaticResource PhoneFontFamilyNormal}"
    FontSize="{StaticResource PhoneFontSizeNormal}"
    Foreground="{StaticResource PhoneForegroundBrush}"
    SupportedOrientations="Portrait" Orientation="Portrait"
    shell:SystemTray.IsVisible="True">

    <!--LayoutRoot is the root grid where all page content is placed-->
    <Grid x:Name="LayoutRoot" Background="Transparent">
        <Grid.RowDefinitions>
            <RowDefinition Height="Auto"/>
            <RowDefinition Height="*"/>
        </Grid.RowDefinitions>

        <!--TitlePanel contains the name of the application and page title-->
        <StackPanel x:Name="TitlePanel" Grid.Row="0" Margin="12,17,0,28">
            <TextBlock x:Name="ApplicationTitle" Text="MY APPLICATION" Style="{StaticResource PhoneTextNormalStyle}"/>
            <TextBlock x:Name="PageTitle" Text="page name" Margin="9,-7,0,0" Style="{StaticResource PhoneTextTitle1Style}"/>
        </StackPanel>

        <!--ContentPanel - place additional content here-->
        <Grid x:Name="ContentPanel" Grid.Row="1" Margin="12,0,12,0">
            <ListBox Grid.Column="2" Name="listBox1" ItemsSource="{Binding strs}">
                <ListBox.ItemTemplate>
                    <DataTemplate>
                        <StackPanel Orientation="Horizontal">
                            <TextBlock Text="{Binding}" />
                        </StackPanel>
                    </DataTemplate>
                </ListBox.ItemTemplate>
                <ItemsControl.ItemsPanel>
                    <ItemsPanelTemplate>
                        <StackPanel Orientation="Vertical" />
                    </ItemsPanelTemplate>
                </ItemsControl.ItemsPanel>
            </ListBox>
            <Button Content="Button" Height="72" HorizontalAlignment="Left" Margin="86,176,0,0" Name="button1" VerticalAlignment="Top" Width="160" Click="button1_Click"/>
        </Grid>
    </Grid>
 
    <!--Sample code showing usage of ApplicationBar-->
    <!--<phone:PhoneApplicationPage.ApplicationBar>
        <shell:ApplicationBar IsVisible="True" IsMenuEnabled="True">
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button1.png" Text="Button 1"/>
            <shell:ApplicationBarIconButton IconUri="/Images/appbar_button2.png" Text="Button 2"/>
            <shell:ApplicationBar.MenuItems>
                <shell:ApplicationBarMenuItem Text="MenuItem 1"/>
                <shell:ApplicationBarMenuItem Text="MenuItem 2"/>
            </shell:ApplicationBar.MenuItems>
        </shell:ApplicationBar>
    </phone:PhoneApplicationPage.ApplicationBar>-->

</phone:PhoneApplicationPage>
后台代码中，我们声明默认绑定的ObservableCollection：ObservableCollection<string> strs
定义一个test类，这个类中同样定义一个名为strs的ObservableCollection<string>
页面初始化以后设置DataContext为this
Code:
protected override void  OnNavigatedTo(NavigationEventArgs e) 
        {
            DataContext = this;
        }
在Button点击以后设置DataContext为test类的实例
Code:
private void button1_Click(object sender, RoutedEventArgs e)
{
    DataContext = _test;
}
全部code behind代码如下：
Code:
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.Navigation;
using System.Windows.Shapes;
using Microsoft.Phone.Controls;
using System.Collections.ObjectModel;



namespace HelloWP7
{
    public partial class MainPage : PhoneApplicationPage
    {
        private ObservableCollection<string> _strs; 
        public ObservableCollection<string> strs { get { return _strs; } }

        public test _test;

        // Constructor
        public MainPage()
        {
            _strs = new ObservableCollection<String> { "hello1", "hello2" };
            _test = new test();
            InitializeComponent();
        }

        protected override void  OnNavigatedTo(NavigationEventArgs e) 
        {
            DataContext = this;
        }

        private void button1_Click(object sender, RoutedEventArgs e)
        {
            DataContext = _test;
        }
    }

    public class test
    {
        private ObservableCollection<string> _strs;
        public ObservableCollection<string> strs { get { return _strs; } }

        public test()
        {
            _strs = new ObservableCollection<String> { "world1", "world2" };
        }
    };
}