DataTable 转换为ArrayList 再转换成 json 格式

//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].ToString());
        //    }
        //    arrayList.Add(dictionary); //ArrayList集合中添加键值
        //}
        //return javaScriptSerializer.Serialize(arrayList);  //返回一个json字符串