在该窗体上，放置一个按钮、一个标签。单击按钮时，在标签上显示当前系统时间。

<img src="https://img-blog.youkuaiyun.com/20141023151840254?watermark/2/text/aHR0cDovL2Jsb2cuY3Nkbi5uZXQvdTAxMjM2OTE3NQ==/font/5a6L5L2T/fontsize/400/fill/I0JBQkFCMA==/dissolve/70/gravity/SouthEast" alt="" />using System;
using System.Collections.Generic;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Linq;
using System.Text;
using System.Windows.Forms;

namespace WindowsFormsApplication1
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void button1_Click(object sender, EventArgs e)
        {
            DateTime date = DateTime.Now;
            label1.Text = date.ToString();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            button1.Text = "单击该按钮显示系统当前时间";
            
        }

        private void label1_Click(object sender, EventArgs e)
        {
           



        }
    }
}