/// <summary>
        /// 将DataTable转换为标准的CSV字符串
        /// </summary>
        /// <param name="dataTable"></param>
        /// <param name="createTitle">是否添加标题</param>
        /// <returns></returns>
        public static string ToCsv2(this DataTable dataTable, bool createTitle = false)
        {
            var builder = new StringBuilder();

            // 添加列标题
            if (createTitle)
            {
                var columnTitles = string.Join(",", dataTable.Columns.Cast<DataColumn>().Select(column => $"\"{column.ColumnName}\""));
                builder.AppendLine(columnTitles);
            }

            // 添加数据行
            foreach (DataRow row in dataTable.Rows)
            {
                var fields = row.ItemArray.Select(field => field is DBNull ? "NULL" : $"\"{field.ToString().Replace("\"", "\"\"")}\"");
                var line = string.Join(",", fields);
                builder.AppendLine(line);
            }

            return builder.ToString();
        }