c#-无法访问Windows Phone中的MessageBox类

我正在创建Windows运行时应用程序,但似乎无权访问MessageBox类.文档指出它位于System.Windows命名空间中,因此我添加了它,但仍然无权访问MessageBox类.using System.Windows;public sealed partial class BillPage :...

我正在创建Windows运行时应用程序,但似乎无权访问MessageBox类.文档指出它位于System.Windows命名空间中,因此我添加了它,但仍然无权访问MessageBox类.

using System.Windows;
public sealed partial class BillPage : Page
{

    private Edge myEdge;
    public BillPage()
    {
        this.InitializeComponent();
        MessageBox.Show("Test", "Test");           
    }
}

知道发生了什么吗？我只是白痴还是什么？
文档：http://msdn.microsoft.com/en-us/library/windowsphone/develop/system.windows.messagebox(v=vs.105).aspx

完整代码：

using EdgeApp.Common;
using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Runtime.InteropServices.WindowsRuntime;
using Windows.Foundation;
using Windows.Foundation.Collections;
using Windows.Graphics.Display;
using Windows.UI.ViewManagement;
using Windows.UI.Xaml;
using Windows.UI.Xaml.Controls;
using Windows.UI.Xaml.Controls.Primitives;
using Windows.UI.Xaml.Data;
using Windows.UI.Xaml.Input;
using Windows.UI.Xaml.Media;
using Windows.UI.Xaml.Navigation;
using System.Windows;

// The Basic Page item template is documented at http://go.microsoft.com/fwlink/?LinkID=390556

namespace EdgeApp
{

    public sealed partial class BillPage : Page
    {
        private NavigationHelper navigationHelper;
        private ObservableDictionary defaultViewModel = new ObservableDictionary();
        private Edge myEdge;
        public BillPage()
        {
            this.InitializeComponent();
            myEdge = new Edge();
            this.navigationHelper = new NavigationHelper(this);
            this.navigationHelper.LoadState += this.NavigationHelper_LoadState;
            this.navigationHelper.SaveState += this.NavigationHelper_SaveState;

        }


        public NavigationHelper NavigationHelper
        {
            get { return this.navigationHelper; }
        }

        public ObservableDictionary DefaultViewModel
        {
            get { return this.defaultViewModel; }
        }


        private void NavigationHelper_LoadState(object sender, LoadStateEventArgs e)
        {
        }


        private void NavigationHelper_SaveState(object sender, SaveStateEventArgs e)
        {
        }

        #region NavigationHelper registration

        protected override void OnNavigatedTo(NavigationEventArgs e)
        {
            this.navigationHelper.OnNavigatedTo(e);
        }

        protected override void OnNavigatedFrom(NavigationEventArgs e)
        {
            this.navigationHelper.OnNavigatedFrom(e);
        }

        #endregion

        private void MessageBoxTest(object sender, RoutedEventArgs e)
        {

            MessageBox.Show("text");

        }
    }
}

解决方法:

在Windows Runtime App中,MessageBox可以通过以下代码显示：

new MessageDialog("Your Message Content").ShowAsync();