更新DataTable的方法

 foreach(DataRow dr in dt.Rows)
            {
                dr.BeginEdit();//对datatable中的数据进行更新
                foreach(DataColumn column in dr.Table.Columns)
                {
                    string colstr = dr[column.ColumnName].ToString();
                    if (colstr.Length > 32)
                    {
                        dr[column.ColumnName] = colstr.Substring(0, 32) + "……";
                    }
                }
                dr.EndEdit();
            }