#region datatable轉換json /ToJsonList(DataTable dt)
        /// <summary>
        /// datatable轉換json
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string ToJsonList(DataTable dt)
        {
            StringBuilder jsonString = new StringBuilder();
            jsonString.Append("[");
            DataRowCollection drc = dt.Rows;
            for (int i = 0; i < drc.Count; i++)
            {
                jsonString.Append("{");
                jsonString.Append("\"xh\":");
                jsonString.Append((i + 1).ToString() + ",");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    string strKey = dt.Columns[j].ColumnName;
                    string strValue = drc[i][j].ToString();
                    Type type = dt.Columns[j].DataType;



                    jsonString.Append("\"" + strKey + "\":");
                    strValue = StringFormat(strValue, type);
                    if (j < dt.Columns.Count - 1)
                    {
                        jsonString.Append(strValue + ",");
                    }
                    else
                    {
                        jsonString.Append(strValue);
                    }
                }
                jsonString.Append("},");
            }
            if (jsonString.Length > 1)
            {
                jsonString.Remove(jsonString.Length - 1, 1);
            }
            jsonString.Append("]");

            string str = jsonString.ToString();
            return jsonString.ToString();
        } 
        #endregion