程式設計工藝大師

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
    {
        int c = 0,d=0;
        public Form1()
        {
         
            InitializeComponent();
        }

        private void Form1_Load(object sender, EventArgs e)
        {

        }

        private void button1_Click(object sender, EventArgs e)
        {
         
            c = c + 1;
            button1.Text = c.ToString();
        }

        private void timer1_Tick(object sender, EventArgs e)
        {
            c = c + 1;
            d = c % 3;
         
            if (d == 2)
            {
                button1.BackColor = System.Drawing.Color.FromName("Red");
                button2.BackColor = System.Drawing.Color.FromName("Black");
                button3.BackColor = System.Drawing.Color.FromName("Black");
            }
            else if (d == 1)
            {

                button1.BackColor = System.Drawing.Color.FromName("Black");
                button2.BackColor = System.Drawing.Color.FromName("Yellow");
                button3.BackColor = System.Drawing.Color.FromName("Black");
            }
            else
            {
                button1.BackColor = System.Drawing.Color.FromName("Black");
                button2.BackColor = System.Drawing.Color.FromName("Black");
                button3.BackColor = System.Drawing.Color.FromName("Green");
            }
        }
    }
}