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.

　　ps：后来我依据这个随笔中操作配置文档节点的方法扩展了其功能,使之能够针对所有的XML文档进行相关的节点或属性的读取,添加,修改,更新操作,

详情请参考我的另一篇随笔：这是一个关于XML文档的操作管理器XMLHelper类,类中包括XML文档的创建,文档节点和属性的读取,添加,修改,删除的方法功能的实现

//==============================================
//
// Copyright(C) 2009-2010 连林SoftWare工作室
// All Rights Reserved
//
// FileName: ConfigManager
// Description: 静态方法业务类，用于对C#、ASP.NET中的WinForm & WebForm 项目程序配置文件
// app.config和web.config的[appSettings]和[connectionStrings]节点进行新增、修改、删除和读取相关的操作。
//
// Author: Wang Lian Lin(王连林)
// CLR版本: 2.0.50727.42
// MachineName: WLL
// 注册组织名: WLL
// Created By Wang Lian Lin(王连林) at 2009-3-9 22:04:45
// Email: LianLin.Wang@163.com
// http://chnboy.cnblogs.com //
//==============================================
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=1,
WebConfig=2
}

/// <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;
}

}