config文件操作类

using System; 
using System.Xml; 
using System.Configuration; 
using System.Collections; 
using System.Reflection; 
using System.Diagnostics;
namespace InstallSetting 
{ 
    public class AppConfigOper : System.Configuration.AppSettingsReader 
    { 
        public string docName = String.Empty; 
        private XmlNode node = null;

        public AppConfigOper(string file) 
        { 
            docName = file; 
        }
        public bool SetValue(string key, string value) 
        { 
            XmlDocument cfgDoc = new XmlDocument(); 
            cfgDoc.Load(docName); 
            node = cfgDoc.SelectSingleNode("//appSettings"); 
            if (node == null) 
            { 
                throw new System.InvalidOperationException("appSettings section not found"); 
            } 
            try 
            { 
                // XPath select setting "add" element that contains this key       
                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']"); 
                if (addElem != null) 
                { 
                    addElem.SetAttribute("value", value); 
                } 
                // not found, so we need to add the element, key and value 
                else 
                { 
                    XmlElement entry = cfgDoc.CreateElement("add"); 
                    entry.SetAttribute("key", key); 
                    entry.SetAttribute("value", value); 
                    node.AppendChild(entry); 
                } 
                //save it 
                saveConfigDoc(cfgDoc, docName); 
                return true; 
            } 
            catch 
            { 
                return false; 
            } 
        }

        public bool SetWebServiceUrl(string Url) {
            XmlDocument cfgDoc = new XmlDocument();
            cfgDoc.Load(docName);
            node = cfgDoc.SelectSingleNode("//IDVerifyDemo.Properties.Settings");
            if (node == null)
            {
                throw new System.InvalidOperationException("setting section not found");
            }
            try
            {
                // XPath select setting "add" element that contains this key       
                XmlElement addElem = (XmlElement)node.SelectSingleNode("//setting[@name='IDVerifyDemo_SendAccessInfo_VisitService']");
                if (addElem != null)
                {
                   // addElem.SelectSingleNode("value") .Value = Url;
                    addElem.SelectSingleNode("value").InnerText = Url;
                    //save it 
                    saveConfigDoc(cfgDoc, docName);
                }
                return true;
            }
            catch(Exception )
            {
                return false;
            } 
        }

        //<connectionStrings>
    //<add name="connString" connectionString="Provider=Microsoft.Jet.OleDb.4.0;Data Source=d:\Card.mdb;User ID='admin';Jet OLEDB:Database Password='123'"/>
  //</connectionStrings>

        public bool  setDataSource(string url){
            try
            {

                XmlDocument cfgDoc = new XmlDocument();
                XmlNode node = null;
                cfgDoc.Load(docName);
                node = cfgDoc.SelectSingleNode("//connectionStrings/add");
                XmlAttribute xmlattr = node.Attributes["connectionString"];
                xmlattr.Value = url;
                saveConfigDoc(cfgDoc, docName);
                return true;
            }
            catch(Exception ex)
            {
                return false;
            }
         }

        public bool SetLogPath(string Url)
        {
            XmlDocument cfgDoc = new XmlDocument();
            cfgDoc.Load(docName);
            node = cfgDoc.SelectSingleNode("//log4net/appender/file");
            if (node == null)
            {
                throw new System.InvalidOperationException("log4net not found");
            }
            try
            {

                if (node != null)
                {
                    // addElem.SelectSingleNode("value") .Value = Url;
                    XmlAttribute xmlattr = node.Attributes["value"];
                    xmlattr.Value = Url;
                    //save it 
                    saveConfigDoc(cfgDoc, docName);
                }
                return true;
            }
            catch (Exception)
            {
                return false;
            }
        }

        private void saveConfigDoc(XmlDocument cfgDoc, string cfgDocPath) 
        { 
            try 
            { 
                XmlTextWriter writer = new XmlTextWriter(cfgDocPath, null); 
                writer.Formatting = Formatting.Indented; 
                cfgDoc.WriteTo(writer); 
                writer.Flush(); 
                writer.Close(); 
                return; 
            } 
            catch 
            { 
                throw; 
            } 
        } 
    } 
}