DataTable ，XML和JSON相互转化

网上搜集的，保留下来了，有需要的拿去！
private string DataTable2Xml(DataTable dt)
        {
            StringBuilder xmlBuilder = new StringBuilder();
            xmlBuilder.Append("<?xml version=\"1.0\" encoding=\"utf-8\" ?>");
            xmlBuilder.Append("<documentElement>");
            xmlBuilder.Append("<" + dt.TableName + ">"); 

            for (int i = ; i < dt.Rows.Count; i++)
            {
                //xmlBuilder.Append("<" + dt.TableName + ">");
                for (int j = ; j < dt.Columns.Count; j++)
                {
                    xmlBuilder.Append("<" + dt.Columns[j].ColumnName + ">");
                    xmlBuilder.Append(dt.Rows[i][j].ToString());
                    xmlBuilder.Append("</" + dt.Columns[j].ColumnName + ">");
                }
                //xmlBuilder.Append("</" + dt.TableName + ">");
            }
            xmlBuilder.Append("</" + dt.TableName + ">"); 

            xmlBuilder.Append("</documentElement>");
            return xmlBuilder.ToString();
        } 

        private string DataTable2Json(DataTable dt,bool withTableName)
        {
            StringBuilder jsonBuilder = new StringBuilder();
            if (withTableName)
            {
                jsonBuilder.Append("{\"");
                jsonBuilder.Append(dt.TableName);
                jsonBuilder.Append("\":");
            }
            jsonBuilder.Append("[");
            for (int i = ; i < dt.Rows.Count; i++)
            {
                jsonBuilder.Append("{");
                for (int j = ; j < dt.Columns.Count; j++)
                {
                    jsonBuilder.Append("\"");
                    jsonBuilder.Append(dt.Columns[j].ColumnName);
                    jsonBuilder.Append("\":\"");
                    jsonBuilder.Append(dt.Rows[i][j].ToString());
                    jsonBuilder.Append("\",");
                }
                jsonBuilder.Remove(jsonBuilder.Length - , );
                jsonBuilder.Append("},");
            }
            jsonBuilder.Remove(jsonBuilder.Length - , );
            jsonBuilder.Append("]");
            if(withTableName)jsonBuilder.Append("}");
            return jsonBuilder.ToString();
        }

 #region DataTable 转换为Json 字符串
    /// <summary>
    /// DataTable 对象 转换为Json 字符串
    /// </summary>
    /// <param name="dt"></param>
    /// <returns></returns>
    public static string ToJson(this DataTable dt)
    {
        JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
        javaScriptSerializer.MaxJsonLength = Int32.MaxValue; //取得最大数值
        ArrayList arrayList = new ArrayList();
        foreach (DataRow dataRow in dt.Rows)
        {
            Dictionary<string, object> dictionary = new Dictionary<string, object>();  //实例化一个参数集合
            foreach (DataColumn dataColumn in dt.Columns)
            {
                dictionary.Add(dataColumn.ColumnName, dataRow[dataColumn.ColumnName].ToStr());
            }
            arrayList.Add(dictionary); //ArrayList集合中添加键值
        }

        return javaScriptSerializer.Serialize(arrayList);  //返回一个json字符串
    }
    #endregion

    #region Json 字符串 转换为 DataTable数据集合
    /// <summary>
    /// Json 字符串 转换为 DataTable数据集合
    /// </summary>
    /// <param name="json"></param>
    /// <returns></returns>
    public static DataTable ToDataTable(this string json)
    {
        DataTable dataTable = new DataTable();  //实例化
        DataTable result;
        try
        {
            JavaScriptSerializer javaScriptSerializer = new JavaScriptSerializer();
            javaScriptSerializer.MaxJsonLength = Int32.MaxValue; //取得最大数值
            ArrayList arrayList = javaScriptSerializer.Deserialize<ArrayList>(json);
            if (arrayList.Count > )
            {
                foreach (Dictionary<string, object> dictionary in arrayList)
                {
                    if (dictionary.Keys.Count<string>() == )
                    {
                        result = dataTable;
                        return result;
                    }
                    if (dataTable.Columns.Count == )
                    {
                        foreach (string current in dictionary.Keys)
                        {
                            dataTable.Columns.Add(current, dictionary[current].GetType());
                        }
                    }
                    DataRow dataRow = dataTable.NewRow();
                    foreach (string current in dictionary.Keys)
                    {
                        dataRow[current] = dictionary[current];
                    }

                    dataTable.Rows.Add(dataRow); //循环添加行到DataTable中
                }
            }
        }
        catch
        {
        }
        result = dataTable;
        return result;
    }
    #endregion

/// <summary>
        /// 将json转换为DataTable
        /// </summary>
        /// <param name="strJson">得到的json</param>
        /// <returns></returns>
        private DataTable JsonToDataTable(string strJson)
        {
            //转换json格式
            strJson = strJson.Replace(",\"", "*\"").Replace("\":", "\"#").ToString();
            //取出表名
            var rg = new Regex(@"(?<={)[^:]+(?=:\[)", RegexOptions.IgnoreCase);
            string strName = rg.Match(strJson).Value;
            DataTable tb = null;
            //去除表名
            strJson = strJson.Substring(strJson.IndexOf("[") + );
            strJson = strJson.Substring(, strJson.IndexOf("]"));

            //获取数据
            rg = new Regex(@"(?<={)[^}]+(?=})");
            MatchCollection mc = rg.Matches(strJson);
            for (int i = ; i < mc.Count; i++)
            {
                string strRow = mc[i].Value;
                string[] strRows = strRow.Split('*');

                //创建表
                if (tb == null)
                {
                    tb = new DataTable();
                    tb.TableName = strName;
                    foreach (string str in strRows)
                    {
                        var dc = new DataColumn();
                        string[] strCell = str.Split('#');

                        if (strCell[].Substring(, ) == "\"")
                        {
                            int a = strCell[].Length;
                            dc.ColumnName = strCell[].Substring(, a - );
                        }
                        else
                        {
                            dc.ColumnName = strCell[];
                        }
                        tb.Columns.Add(dc);
                    }
                    tb.AcceptChanges();
                }

                //增加内容
                DataRow dr = tb.NewRow();
                for (int r = ; r < strRows.Length; r++)
                {
                    dr[r] = strRows[r].Split('#')[].Trim().Replace("，", ",").Replace("：", ":").Replace("\"", "");
                }
                tb.Rows.Add(dr);
                tb.AcceptChanges();
            }

            return tb;
        }

public static DataTable JsonToDataTable(string strJson)
        {
            //取出表名
            Regex rg = new Regex(@"(?<={)[^:]+(?=:/[)", RegexOptions.IgnoreCase);
            string strName = rg.Match(strJson).Value;
            DataTable tb = null;
            //去除表名
            strJson = strJson.Substring(strJson.IndexOf("[") + );
            strJson = strJson.Substring(, strJson.IndexOf("]"));

            //获取数据
            rg = new Regex(@"(?<={)[^}]+(?=})");
            MatchCollection mc = rg.Matches(strJson);
            for (int i = ; i < mc.Count; i++)
            {
                string strRow = mc[i].Value;
                string[] strRows = strRow.Split(',');

                //创建表
                if (tb == null)
                {
                    tb = new DataTable();
                    tb.TableName = strName;
                    foreach (string str in strRows)
                    {
                        DataColumn dc = new DataColumn();
                        string[] strCell = str.Split(':');
                        dc.ColumnName = strCell[].ToString();
                        tb.Columns.Add(dc);
                    }
                    tb.AcceptChanges();
                }

                //增加内容
                DataRow dr = tb.NewRow();
                for (int r = ; r < strRows.Length; r++)
                {
                    dr[r] = strRows[r].Split(':')[].Trim().Replace("，", ",").Replace("：", ":").Replace("/"", "");
                }
                tb.Rows.Add(dr);
                tb.AcceptChanges();
            }

            return tb;
        }