如何从表格no导入excel文件，以及用户在数据适配器中从原始no导入excel文件

  using (OleDbConnection con = new OleDbConnection(conStr))
            {
                using (OleDbCommand cmd = new OleDbCommand())
                {
                    cmd.Connection = con;
                    con.Open();
                    DataTable dtExcelSchema = con.GetOleDbSchemaTable(OleDbSchemaGuid.Tables, null);
                    string sheetNo ="Sheet" +txtImportExcelSheetNo.Text+"$";
                    sheetName = dtExcelSchema.Rows[0]["TABLE_NAME"].ToString();

                        string toRow = txtImportExcelToRw.Text;
                        string fromRow = txtImportExcelfromRw.Text;
                    con.Close();
                }
            }

            //Read Data from the First Sheet.
            using (OleDbConnection con = new OleDbConnection(conStr))
            {
                using (OleDbCommand cmd = new OleDbCommand())
                {
                    using (OleDbDataAdapter oda = new OleDbDataAdapter())
                    {

                        DataTable dt = new DataTable();
                        cmd.CommandText = "SELECT * From [" + sheetName + "]";
                        cmd.Connection = con;
                        con.Open();
                        oda.SelectCommand = cmd;
                        oda.Fill(dt);
                        con.Close();

                        //Populate DataGridView.

                    }
  using (OleDbConnection con = new OleDbConnect