将datatable 转换成json数据格式

/// <summary>
        ///  将datatable 转换成json数据格式
        /// </summary>
        /// <param name="dt"></param>
        /// <returns></returns>
        private string DataTableToJson(DataTable dt)
        {
            StringBuilder strJson = new StringBuilder();
            strJson.Append("[");
            for (int i = 0; i < dt.Rows.Count; i++)
            {
                strJson.Append("{");
                for (int j = 0; j < dt.Columns.Count; j++)
                {
                    strJson.Append("\"" + dt.Columns[j].ColumnName.Trim() + "\"");
                    strJson.Append(":");
                    strJson.Append("\"" + dt.Rows[i][j].ToString().Trim() + "\"");
                    if ((j + 1) != dt.Columns.Count)
                        strJson.Append(",");
                }
                strJson.Append("}");
                if ((i + 1) != dt.Rows.Count)
                    strJson.Append(",");
            }
            strJson.Append("]");
            return strJson.ToString();
        }