datatable数据列全转换为字符串

         /// <summary>

        /// datatable数据列全转换为字符串
        /// </summary>
        /// <param name="sourceTable"></param>
        /// <returns></returns>
        public static DataTable ConvertDataColumType(DataTable sourceTable)
        {
            //克隆表结构
            DataTable dtResult = sourceTable.Clone();
            List<string> lsCol = GetDateTimeColName(ref dtResult);
            foreach (DataRow row in sourceTable.Rows)
            {
                DataRow rowNew = dtResult.NewRow();
                foreach (DataColumn itemCol in dtResult.Columns)
                {
                    if (!lsCol.Contains(itemCol.ColumnName))
                    {
                        rowNew[itemCol] = row[itemCol.ColumnName];
                    }
                    else
                    {
                        string sColValue = !row.IsNull(itemCol.ColumnName)
                            ? DateTime.Parse(row[itemCol.ColumnName].ToString()).ToString("yyyy-MM-dd HH:mm:ss")
                            : "";
                        rowNew[itemCol] = sColValue;
                    }
                }
                dtResult.Rows.Add(rowNew);
            }
            return dtResult;
        }

        public static List<string> GetDateTimeColName(ref DataTable dtResult)
        {
            List<string> lsCol = new List<string>();
            foreach (DataColumn col in dtResult.Columns)
            {
                if (col.DataType == typeof (System.DateTime)
                    && !lsCol.Contains(col.ColumnName))
                {
                    lsCol.Add(col.ColumnName);
                }
                //修改列类型
                col.DataType = typeof(string);
            }
            return lsCol;
        }