C#怎样使TextBox里内容更新时它的垂直下拉条自动处于最下方，以显示最新的内容
如题

------解决方案--------------------
private void button1_Click(object sender, EventArgs e)
{
textBox1.AppendText(DateTime.Now.ToString() + "\r\n ");
textBox1.SelectionStart = textBox1.Text.Length;
textBox1.ScrollToCaret();
}