private void button1_Click(object sender, EventArgs e) { timer1.Start(); } private void button2_Click(object sender, EventArgs e) { timer1.Stop(); } int i; private void timer1_Tick(object sender, EventArgs e){i=i+1; if(i==7) i=0;switch (i) { case 1: textBox1.Text = "黄"; textBox1.BackColor = Color.Yellow; break; case 2: case 3: textBox1.Text = "红"; textBox1.BackColor = Color.Red; break; case 4: case 5: case 6: textBox1.Text = "绿"; textBox1.BackColor = Color.Green; break;