dataTable转换成Json格式

 #region dataTable转换成Json格式
        /// <summary>
        /// 
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        public static string DataTableToJson(DataTable dt)
        {
            if (dt == null)
                return string.Empty;
            StringBuilder Json = new StringBuilder();
            Json.Append("[");
            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();
        }

        #endregion

 或者

 private string GetJson(DataTable dt)
        {
            StringBuilder sb = new StringBuilder();
            sb.Append("[");
            foreach (DataRow row in dt.Rows)
            {
                sb.Append("{");
                foreach (DataColumn column in dt.Columns)
                {
                    string value = row[column.ColumnName].ToString();
                    value = formatStr(value);
                    sb.Append(column.ColumnName + ":\"" + value + "\",");
                }
                if (sb.ToString().EndsWith(","))
                {
                    sb.Remove(sb.Length - 1, 1);
                }
                sb.Append("},");
            }
            if (sb.ToString().EndsWith(","))
            {
                sb.Remove(sb.Length - 1, 1);
            }
            sb.Append("]");
            return sb.ToString();
        }

        private string formatStr(string str)
        {
            if (str.Contains("\""))
            {
                str = str.Replace("\"", "");
            }
            if (str.Contains("\r\n"))
            {
                str = str.Replace("\r\n", "");
            }
            return str;
        }