关于C＃和ASP.NET中对App.config和Web.config文件里的[appSettings]和[connectionStrings]节点进行新增、修改、删除和读取相关的操作

最近我做的一些项目,经常需要用到对应用程序的配置文件操作,如app.config和web.config的配置文件,特别是对配置文件中的[appSettings]和[connectionStrings]两个节点常常进行新增、修改、删除和读取相关的操作的，所以,我自己就亲手把这些相关的操作都封装到一个配置文件管理器中,用静态的方法来调用便可,以下是我的实现,以资参考.

 using System;
 using System.Data;
 using System.Configuration;
 using System.Web;
 using System.Collections.Generic;
 using System.Text;
 using System.Xml;

 public enum ConfigurationFile
 {
     AppConfig=,
     WebConfig=
 }

 /// <summary>
 /// ConfigManager 应用程序配置文件管理器
 /// </summary>
 public class ConfigManager
 {
     public ConfigManager()
     {
         //
         // TODO: 在此处添加构造函数逻辑
         //
     }

     /// <summary>
     /// 对[appSettings]节点依据Key值读取到Value值，返回字符串
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="key">要读取的Key值</param>
     /// <returns>返回Value值的字符串</returns>
     public static string ReadValueByKey(ConfigurationFile configurationFile, string key)
     {
         string value = string.Empty;
         string filename = string.Empty;
         if (configurationFile.ToString()==ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }

         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件

         XmlNode node = doc.SelectSingleNode("//appSettings");   //得到[appSettings]节点

         ////得到[appSettings]节点中关于Key的子节点
         XmlElement element = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");

         if (element != null)
         {
             value = element.GetAttribute("value");
         }

         return value;
     }

     /// <summary>
     /// 对[connectionStrings]节点依据name值读取到connectionString值，返回字符串
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="name">要读取的name值</param>
     /// <returns>返回connectionString值的字符串</returns>
     public static string ReadConnectionStringByName(ConfigurationFile configurationFile, string name)
     {
         string connectionString = string.Empty;
         string filename = string.Empty;
         if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }

         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件

         XmlNode node = doc.SelectSingleNode("//connectionStrings");   //得到[appSettings]节点

         ////得到[connectionString]节点中关于name的子节点
         XmlElement element = (XmlElement)node.SelectSingleNode("//add[@name='" + name + "']");

         if (element != null)
         {
             connectionString = element.GetAttribute("connectionString");
         }

         return connectionString;
     }

     /// <summary>
     /// 更新或新增[appSettings]节点的子节点值，存在则更新子节点Value,不存在则新增子节点，返回成功与否布尔值
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="key">子节点Key值</param>
     /// <param name="value">子节点value值</param>
     /// <returns>返回成功与否布尔值</returns>
     public static bool UpdateOrCreateAppSetting(ConfigurationFile configurationFile, string key, string value)
     {
         bool isSuccess = false;
         string filename = string.Empty;
         if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }

         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件

         XmlNode node = doc.SelectSingleNode("//appSettings");   //得到[appSettings]节点

         try
         {
             ////得到[appSettings]节点中关于Key的子节点
             XmlElement element = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");

             if (element != null)
             {
                 //存在则更新子节点Value
                 element.SetAttribute("value", value);
             }
             else
             {
                 //不存在则新增子节点
                 XmlElement subElement = doc.CreateElement("add");
                 subElement.SetAttribute("key", key);
                 subElement.SetAttribute("value", value);
                 node.AppendChild(subElement);
             }

             //保存至配置文件(方式一)
             using (XmlTextWriter xmlwriter = new XmlTextWriter(filename, null))
             {
                 xmlwriter.Formatting = Formatting.Indented;
                 doc.WriteTo(xmlwriter);
                 xmlwriter.Flush();
             }

             isSuccess = true;
         }
         catch (Exception ex)
         {
             isSuccess = false;
             throw ex;
         }

         return isSuccess;
     }

     /// <summary>
     /// 更新或新增[connectionStrings]节点的子节点值，存在则更新子节点,不存在则新增子节点，返回成功与否布尔值
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="name">子节点name值</param>
     /// <param name="connectionString">子节点connectionString值</param>
     /// <param name="providerName">子节点providerName值</param>
     /// <returns>返回成功与否布尔值</returns>
     public static bool UpdateOrCreateConnectionString(ConfigurationFile configurationFile, string name, string connectionString, string providerName)
     {
         bool isSuccess = false;
         string filename = string.Empty;
         if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }

         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件
         XmlNode node = doc.SelectSingleNode("//connectionStrings");   //得到[connectionStrings]节点

         try
         {
             ////得到[connectionStrings]节点中关于Name的子节点
             XmlElement element = (XmlElement)node.SelectSingleNode("//add[@name='" + name + "']");

             if (element != null)
             {
                 //存在则更新子节点
                 element.SetAttribute("connectionString", connectionString);
                 element.SetAttribute("providerName", providerName);
             }
             else
             {
                 //不存在则新增子节点
                 XmlElement subElement = doc.CreateElement("add");
                 subElement.SetAttribute("name", name);
                 subElement.SetAttribute("connectionString", connectionString);
                 subElement.SetAttribute("providerName", providerName);
                 node.AppendChild(subElement);
             }

             //保存至配置文件(方式二)
             doc.Save(filename);
             isSuccess = true;
         }
         catch (Exception ex)
         {
             isSuccess = false;
             throw ex;
         }
         return isSuccess;
     }

     /// <summary>
     /// 删除[appSettings]节点中包含Key值的子节点，返回成功与否布尔值
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="key">要删除的子节点Key值</param>
     /// <returns>返回成功与否布尔值</returns>
     public static bool DeleteByKey(ConfigurationFile configurationFile, string key)
     {
         bool isSuccess = false;
         string filename = string.Empty;
         if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }
         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件
         XmlNode node = doc.SelectSingleNode("//appSettings");   //得到[appSettings]节点
         ////得到[appSettings]节点中关于Key的子节点
         XmlElement element = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");

         if (element != null)
         {
             //存在则删除子节点
             element.ParentNode.RemoveChild(element);
         }
         else
         {
             //不存在
       }
         try
         {
             //保存至配置文件(方式一)
             using (XmlTextWriter xmlwriter = new XmlTextWriter(filename, null))
             {
                 xmlwriter.Formatting = Formatting.Indented;
                 doc.WriteTo(xmlwriter);
                 xmlwriter.Flush();
             }
             isSuccess = true;
         }
         catch (Exception ex)
         {
             isSuccess = false;
         }
         return isSuccess;
     }

     /// <summary>
     /// 删除[connectionStrings]节点中包含name值的子节点，返回成功与否布尔值
     /// </summary>
     /// <param name="configurationFile">要操作的配置文件名称,枚举常量</param>
     /// <param name="name">要删除的子节点name值</param>
     /// <returns>返回成功与否布尔值</returns>
     public static bool DeleteByName(ConfigurationFile configurationFile, string name)
     {
         bool isSuccess = false;
         string filename = string.Empty;
         if (configurationFile.ToString() == ConfigurationFile.AppConfig.ToString())
         {
             filename = System.Windows.Forms.Application.ExecutablePath + ".config";
         }
         else
         {
             filename = System.AppDomain.CurrentDomain.BaseDirectory + "web.config";
         }

         XmlDocument doc = new XmlDocument();
         doc.Load(filename); //加载配置文件
         XmlNode node = doc.SelectSingleNode("//connectionStrings");   //得到[connectionStrings]节点
         ////得到[connectionStrings]节点中关于Name的子节点
         XmlElement element = (XmlElement)node.SelectSingleNode("//add[@name='" + name + "']");
         if (element != null)
         {
             //存在则删除子节点
             node.RemoveChild(element);
         }
         else
         {
             //不存在
       }
         try
         {
             //保存至配置文件(方式二)
             doc.Save(filename);
             isSuccess = true;
         }
         catch (Exception ex)
         {
             isSuccess = false;
         }
         return isSuccess;
     }
 }