private void 另存为AToolStripMenuItem_Click(object sender, EventArgs e)
        {
            SaveFileDialog dlg = new SaveFileDialog();
            dlg.Title = "保存为";
            dlg.Filter = "txt file(*.txt)[*.txt]all files(*.*)|*.*";
            char [] parm = { "\n" };
            string lines = richTextBox1.Text.Split(parm);
            int i = 0;
            char [] trimparam = { "\r" };
            foreach (string s in lines)
                lines[i++] = s.TrimEnd(trimparam);
            try
            {
                StreamWriter sw = new StreamWriter(dlg.FileName);
                foreach (string s in lines)
                {
                    sw.WriteLine(s);
                }
                sw.Close();
            }
            catch (Exception ex)
            { MessageBox.Show(ex.ToString(), "提示");
            return;
            }
        }


为什么我用上运行不了、 求解决、谢谢