DataTable工具类

1. DataTable转换为Json

public static string DataTableToJson(string jsonName, DataTable dt)
    {
        StringBuilder Json = new StringBuilder();
        Json.Append("[");
        if (dt.Rows.Count > 0)
        {
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                Json.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    Json.Append("/"" + dt.Columns[j].ColumnName.ToString() + "/":/"" + dt.Rows[i][j].ToString() + "/"");
                    if (j < dt.Columns.Count - 1)
                    {
                        Json.Append(",");
                    }
                }
                Json.Append("}");
                if (i < dt.Rows.Count - 1)
                {
                    Json.Append(",");
                }
            }
        }
        Json.Append("]");
        return Json.ToString();
    }

2.DataTable自增列

    public DataTable GetDataTable(DataTable srcTable)
    {

        bool isContains = srcTable.Columns.Contains("Id");
        if (isContains == false)
        {
            DataTable dstntnTable = new DataTable();
            dstntnTable.Columns.Add("Id", typeof(Int32));
            for (int i = 0; i < srcTable.Columns.Count; i++)
                dstntnTable.Columns.Add(srcTable.Columns[i].ColumnName, srcTable.Columns[i].DataType);
            int srcColCount = srcTable.Columns.Count;
            int srcRowCount = srcTable.Rows.Count;
            int dstntnRowCount = 0;
            for (int j = 0; j < srcRowCount; j++)
            {
                DataRow newRow = dstntnTable.NewRow();
                newRow[0] = (++dstntnRowCount);
                for (int k = 0; k < srcColCount; k++)
                    newRow[k + 1] = srcTable.Rows[j][k];
                dstntnTable.Rows.Add(newRow);
            }
            return dstntnTable;
        }
        return srcTable;
    }

3.DataToXml

 /// <summary>
        /// 生成文件
        /// </summary>
        /// <param name="val"></param>
        /// <param name="filename"></param>
        public void CreateXml(string val, string filename)
        {
            UnicodeEncoding ucode = new UnicodeEncoding();
            StreamWriter sw = new StreamWriter(Server.MapPath(filename));
            sw.WriteLine("<?xml version=/"1.0/" encoding=/"utf-8/"?>");
            sw.WriteLine(val);
            sw.Close();
            sw.Dispose();
        }

        /// <summary>
        /// 转换成XML格式字符串
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public string DataTableToXml(DataTable dt)
        {
            StringBuilder strXml = new StringBuilder();
            strXml.AppendLine("<XmlTable>");
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                strXml.AppendLine(" <rows>");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    strXml.AppendLine("  <" + dt.Columns[j].ColumnName + ">" + dt.Rows[i][j] + "</" + dt.Columns[j].ColumnName + ">");
                }
                strXml.AppendLine(" </rows>");
            }
            strXml.AppendLine("</XmlTable>");
            return strXml.ToString();
        }