form1.cs

Visual C#2005程序设计教程

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

namespace WinApp5_6ListBox
{
    public partial class Form1 : Form
    {
        public Form1()
        {
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {
            for (int i = 2000; i <= 2006; i++)
                lstYears.Items.Add(i);
        }

        private void lstYears_SelectedIndexChanged(object sender, EventArgs e)
        {
            if (lstYears.SelectedIndex == -1)
                return;
            int year=int.Parse(lstYears.SelectedItem.ToString( ));
            if (year % 4 == 0 && year % 100 != 0 || year % 400 == 0)
                lblOut.Text = year + "年是闰年！";
            else
                lblOut.Text = year + "年不是闰年！";
        }

        private void button1_Click(object sender, EventArgs e)
        {
            if (txtInputYear.Text != "")
                lstYears.Items.Add(txtInputYear.Text);
        }

        private void button2_Click(object sender, EventArgs e)
        {
            if (lstYears.SelectedIndex != -1)
                lstYears.Items.Insert(lstYears.SelectedIndex, txtInputYear.Text);
        }

        private void button3_Click(object sender, EventArgs e)
        {
            if (lstYears.SelectedIndex != -1)
                lstYears.Items.Remove(lstYears.SelectedItem);
        }

        private void button4_Click(object sender, EventArgs e)
        {
            lstYears.Items.Clear();
            txtInputYear.Text = "";
            lblOut.Text = "";
        }
    }
}