namespace _12日期选择器
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}

private void Form1_Load(object sender, EventArgs e) { //获取当前时间 int year = DateTime.Now.Year; //当程序运行时就将年份加载进去cboYears for (int i = year; i >=1949; i--) { cboYears.Items.Add(i+"年"); } } private void cboYears_SelectedIndexChanged(object sender, EventArgs e) { //添加月份之前清空之前记录 cboMonths.Items.Clear(); //当选择年份时，加载月份 for (int i = 1; i <= 12; i++) { cboMonths.Items.Add(i+"月"); } } private void cboMonths_SelectedIndexChanged(object sender, EventArgs e) { //定义一个day来存储天数 int day = 0; //加载day之前清空之前记录 cboDays.Items.Clear(); //获得月份 string strmonth = cboMonths.SelectedItem.ToString().Split(new char[] { '月' }, StringSplitOptions.RemoveEmptyEntries)[0]; //获得年份 string strYear = cboYears.SelectedItem.ToString().Split(new char[] { '年' }, StringSplitOptions.RemoveEmptyEntries)[0]; //将年月字符串类型转换成int类型 int year = Convert.ToInt32(strYear); int month = Convert.ToInt32(strmonth); //对month进行多条件判断 switch (month) { case 1: case 3: case 5: case 7: case 8: case 10: case 12:day = 31; break; case 2:if(year%400==0 || year%4==0 && year % 100 != 0) { day = 29; } else { day = 28; } break; default:day = 30; break; } for (int i = 1; i <= day; i++) { cboDays.Items.Add(i+"日"); } }}

}