c#修改xml文件

        /// <summary>
        /// 负责对ReportConfig.xml文件进行修改
        /// </summary>
        /// <param name="id">文档上传到服务器后的名称(注意没有扩展名)</param>
        /// <param name="fileName">文档上传之前的名称(注意没有扩展名)</param>
        /// <returns>成功返回1 失败返回 0</returns>
        protected int ModifyConfig(string id,string fileName)
        {
            string filePath = AppDomain.CurrentDomain.BaseDirectory + "\\ReportConfig.xml";
          
            if (File.Exists(filePath))
            {
                try
                {
                    XmlDocument xmlDoc = new XmlDocument();

                    xmlDoc.Load(filePath);
                    XmlNodeList nodelist = xmlDoc.SelectSingleNode("Reports").ChildNodes;
                    foreach (XmlNode xn in nodelist)
                    {
                        if (xn.Attributes!=null&&xn.Name=="ReportName")
                        {
                            XmlElement xe = xn as XmlElement;

                            string ss = xn.Attributes["attachmentName"].Value;

                            if (xe != null)
                            {

                                //xn.Attributes["attachmentName"].ToString();

                                if (xe.GetAttribute("attachmentName") == fileName)
                                {
                                    xe.SetAttribute("fileName", id);
                                    xmlDoc.Save(filePath);

                                    return 1;
                                }
                            } 
                        }
                    }
                }
                catch (Exception ex)
                {
                    
                    throw ex;
                }
      
            }

            return 0;
        
        }
<Reports> 
 <ReportName fileName="20130620083411" reportMethod="" attachmentName="公众信息文稿、新闻稿">
    <ReportFiled remark="ReportTime" type="" method="1">
    </ReportFiled>
  </ReportName>
  <!--场外通用报告模板-->
  <ReportName fileName="20130620083342" reportMethod="" attachmentName="场外通用报告模板">
    <ReportFiled remark="ReportTime" type="" method="1">
    </ReportFiled>
  </ReportName>
</Reports>