asp.net计算时间差

        protected void Button1_Click(object sender, EventArgs e)
        {
            DateTime time1 = DateTime.Parse(TextBox1.Text);
            DateTime time2 = DateTime.Parse(TextBox2.Text);  //获取两个TextBox中的时间
            System.TimeSpan st = time1.Subtract(time2);    //计算time1-time2
            Label2.Text = st.Days.ToString() + "天" + st.Hours.ToString() + "小时" + st.Minutes.ToString() + "分钟" + st.Seconds.ToString() + "秒";
            Label3.Text =Convert.ToString( st.Days * 24 * 60 + st.Hours * 60 + st.Minutes + st.Seconds / 60)+"分钟";
        }