DataTable to Json

        /// <summary>
        /// DataTable to json
        /// </summary>
        /// <param name="jsonName">返回json的名称</param>
        /// <param name="dt">转换成json的表</param>
        /// <returns></returns>
        public static string DataTableToJson(string jsonName, System.Data.DataTable dt)
        {
            StringBuilder Json = new StringBuilder();
            Json.Append("{\"" + jsonName + "\":[");
            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();
        }