1:  /// <summary>

   2:  /// 修改web.config或app.config文件appSettings配置节中的Add里的value属性

   3:  /// </summary>

   4:  /// <remarks>

   5:  /// 注意，调用该函数后，会使整个Web Application重启，导致当前所有的会话丢失

   6:  /// </remarks>

   7:  /// <param name="key">要修改的键key</param>

   8:  /// <param name="strValue">修改后的value</param>

   9:  /// <exception cref="">找不到相关的键</exception>

  10:  /// <exception cref="">权限不够，无法保存到web.config文件中</exception>

  11:  public static void ModifyAppSettings(string key, string strValue)

  12:  {

  13:      string XPath = "/configuration/appSettings/add[@key='?']";

  14:      XmlDocument domConfig = new XmlDocument();

  15:   

  16:      domConfig.Load(Environment.CurrentDirectory + "/Application1.exe.config");

  17:      XmlNode addKey = domConfig.SelectSingleNode((XPath.Replace("?", key)));

  18:      if (addKey == null)

  19:      {

  20:          throw new ArgumentException("没有找到<add key='" + key + "' value=.../>的配置节");

  21:      }

  22:      addKey.Attributes["value"].InnerText = strValue;

  23:      domConfig.Save(Environment.CurrentDirectory + "/Application1.exe.config");

  24:   

  25:  }

  26:   

  27:  /// <summary>

  28:  /// 获取web.config或app.config文件appSettings配置节中的Add里的value属性

  29:  /// </summary>

  30:  /// <param name="key">要修改的键key</param>

  31:  /// <param name="strValue">修改后的value</param>

  32:  /// <exception cref="">找不到相关的键</exception>

  33:  /// <exception cref="">权限不够，无法保存到web.config文件中</exception>

  34:  public static string GetAppSettings(string key)

  35:  {

  36:      string XPath = "/configuration/appSettings/add[@key='?']";

  37:      XmlDocument domConfig = new XmlDocument();

  38:   

  39:      domConfig.Load(Environment.CurrentDirectory + "/Application1.exe.config");

  40:      XmlNode addKey = domConfig.SelectSingleNode((XPath.Replace("?", key)));

  41:      if (addKey == null)

  42:      {

  43:          throw new ArgumentException("没有找到<add key='" + key + "' value=.../>的配置节");

  44:      }

  45:      return addKey.Attributes["value"].InnerText;

  46:  }