C# ConfigHelper 辅助类介绍

//==============================================
//        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。

//==============================================
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;
    }

}