效果：

MainPage.xaml:

MainPage.xaml.cs 中的Button事件：

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 SilverlightApplication2{    public partial class MainPage : UserControl    {        public MainPage()        {            InitializeComponent();        }        private void OKButton_Click(object sender, RoutedEventArgs e)        {            string dateString;            if (cal.SelectedDate == null)            {                dateString = "
     
      ";            }            else            {                                dateString = cal.SelectedDate.ToString();            }            Mess.Text = "Hi " + name1.Text.ToString() + "\n" + "Selected Date:" + dateString;        }    }}