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