C#计时器

Form1.cs

namespace WindowsFormsApplication6
{
public partial class Form1 : Form
{
public Form1()
{
InitializeComponent();
}
int i = 0;
private void timer1_Tick(object sender, EventArgs e)
{
i++;
txtTime.Text = i.ToString();
}

private void btnStar_Click(object sender, EventArgs e)
{
timer1.Enabled =  true;
}

private void btnStop_Click(object sender, EventArgs e)
{
timer1.Enabled = false;
}

private void button1_Click(object sender, EventArgs e)
{
i = 0;
txtTime.Text = i.ToString();
}
}
}