C#-WinForm-弹窗提示框-如何知道用户点击的是哪个按钮？

private void button1_Click(object sender, EventArgs e)
{
DialogResult dr = MessageBox.Show("我是小飞机！", "我会飞！", MessageBoxButtons.OKCancel);

if (dr == DialogResult.OK)
{
button1.Text = "确定按钮";
}
else if (dr == DialogResult.Cancel)
{
button1.Text = "取消了！";
}
}