程式工藝大師

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, b = 0;

public Form1()
{
InitializeComponent();
}

private void button1_Click(object sender, EventArgs e)
{

c = c + 1;
b = c % 3;
button1.Text = b.ToString();
if (b == 0)
{
button1.BackColor= System.Drawing.Color.Red;
}
else if (b==1)
{
button2.BackColor= System.Drawing.Color.Yellow;
}
else
{
button3.BackColor= System.Drawing.Color.Green;
}
}

private void timer1_Tick(object sender, EventArgs e)
{
c = c + 1;
b = c % 3;
button1.Text = b.ToString();
if (b == 0)
{
button1.BackColor = System.Drawing.Color.Red;
button2.BackColor = System.Drawing.Color.Black;
button3.BackColor = System.Drawing.Color.Black;

}
else if (b == 1)
{
button2.BackColor = System.Drawing.Color.Yellow;
button1.BackColor = System.Drawing.Color.Black;
button3.BackColor = System.Drawing.Color.Black;
}
else
{
button3.BackColor = System.Drawing.Color.Green;
button2.BackColor = System.Drawing.Color.Black;
button1.BackColor = System.Drawing.Color.Black;

}
}
}
}