C#输入日期显示该日期当天为星期几

using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Threading.Tasks;
using System.Windows.Forms;

namespace P47sy1输入日期显示星期几
{
public partial class Form1 : Form
{
enum WeekDay { 星期天, 星期一, 星期二, 星期三, 星期四, 星期五, 星期六 };
public Form1()
{
InitializeComponent();
}

private void btnOk_Click(object sender, EventArgs e)
{

DateTime dt = Convert.ToDateTime(txtDate.Text);
WeekDay wd = (WeekDay)dt.DayOfWeek;
lblShow.Text = "这一天是" + wd + ".";

}
}
}