private void button1_Click_1(object sender, EventArgs e)

        {

            string ex = neirong.Text;

            List<string> d = new List<string>();

            getlist(ex,ref d);

            var ss = d;

        }

        private void getlist(string strs,ref List<string> d)

        {

            if (strs.Length > 290)

            {

                string sy = "";

                string zj = strs.Substring(0, 290);

                int djindex = zj.LastIndexOf('。');

                d.Add(strs.Substring(0, djindex));

                sy = strs.Remove(0, djindex);

                getlist(sy, ref d);

            }

            else

            {

                d.Add(strs);

            }

        }