silverlight 按回车触发按钮事件

silverlight 按回车触发按钮事件简单代码如下：

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;


namespace SilverlightApplication8
{
    public partial class MainPage : UserControl
    {
        public MainPage()
        {
            InitializeComponent();
            TESTButton.Click+=new RoutedEventHandler(TESTButton_Click);
            this.KeyDown += new KeyEventHandler(MainPage_KeyDown);
        }
        void MainPage_KeyDown(object sender,KeyEventArgs E)
        {
            if (e.Key.Equals(Key.Enter))
            {
                TESTButton_Click(null,null);
            }
        }
        void TESTButton_Click(object sender,RoutedEventArgs E)
        {
            messageBox.Show("Hello World!");
        }
    }
}