程序運行界面

源代碼：

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 WindowsFormsApplication1{ public partial class Form1 : Form { public Form1() { InitializeComponent(); } private void button1_Click(object sender, EventArgs e) { if(rad_week.Checked) { string var_week = DateTime.Now.ToString("dddd"); textBox1.Text = var_week; } else if (rad_days.Checked) { string var_year = DateTime.Now.ToString("yyyy"); if(DateTime.IsLeapYear(int.Parse(var_year))) { int var_days = 366; textBox1.Text = var_days.ToString(); } else { int var_days = 365; textBox1.Text = var_days.ToString(); } } else if(rad_monthdays.Checked) { int var_days = DateTime.DaysInMonth(DateTime.Now.Year, DateTime.Now.Month); textBox1.Text = var_days.ToString(); } } }}結語：

學會使用單選框控件及其Checked屬性，會使用DateTime類中得IsLeapYear方法來判斷閏年，熟悉輸出指定日期格式得特殊字符格式，掌握DaysInMonth方法求取某個月得天數(shù)。

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