因为要把程序中的重要参数想保存到config 里，看到圈子里已有公布的代码了，在此谢谢作者
作者及出处 http://singlepine.cnblogs.com/articles/293683.html
1.建立一个class，ReadWriteConfig.cs
using System;
using System.Configuration;
using System.Reflection;
using System.Web;
using System.Xml;
public enum ConfigFileType
{
WebConfig,
AppConfig
}
namespace WebApplication1
{
///
/// Summary description for ReadWriteConfig.
///
public class ReadWriteConfig
{
public string docName = String.Empty;
private XmlNode node=null;
private int _configType;
public int ConfigType
{
get{ return _configType; }
set{ _configType=value; }
}
#region SetValue
public bool SetValue(string key, string value)
{
XmlDocument cfgDoc = new XmlDocument();
loadConfigDoc(cfgDoc);
// retrieve the appSettings node
node = cfgDoc.SelectSingleNode("//appSettings");
if( node == null )
{
throw new 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;
}
}
#endregion
#region saveConfigDoc
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;
}
}
#endregion
#region removeElement
public bool removeElement (string elementKey)
{
try
{
XmlDocument cfgDoc = new XmlDocument();
loadConfigDoc(cfgDoc);
// retrieve the appSettings node
node = cfgDoc.SelectSingleNode("//appSettings");
if( node == null )
{
throw new InvalidOperationException( "appSettings section not found");
}
// XPath select setting "add" element that contains this key to remove
node.RemoveChild( node.SelectSingleNode("//add[@key='" +elementKey +"']") );
saveConfigDoc(cfgDoc,docName);
return true;
}
catch
{
return false;
}
}
#endregion
#region modifyElement
public bool modifyElement (string elementKey)
{
try
{
XmlDocument cfgDoc = new XmlDocument();
loadConfigDoc(cfgDoc);
// retrieve the appSettings node
node = cfgDoc.SelectSingleNode("//appSettings");
if( node == null )
{
throw new InvalidOperationException( "appSettings section not found");
}
// XPath select setting "add" element that contains this key to remove
node.RemoveChild(node.SelectSingleNode("//add[@key='" +elementKey +"']"));
saveConfigDoc(cfgDoc,docName);
return true;
}
catch
{
return false;
}
}
#endregion
#region loadConfigDoc
private XmlDocument loadConfigDoc( XmlDocument cfgDoc )
{
// load the config file
if( Convert.ToInt32(ConfigType)==Convert.ToInt32(ConfigFileType.AppConfig))
{
docName= ((Assembly.GetEntryAssembly()).GetName()).Name;
docName += ".exe.config";
}
else
{
docName=HttpContext.Current.Server.MapPath("web.config");
}
cfgDoc.Load( docName );
return cfgDoc;
}
#endregion
}
}
功能页面=================
WebForm1.aspx===
<%@ Page language="c#" Inherits="WebApplication1.WebForm1" CodeFile="WebForm1.aspx.cs" %>
WebForm1
http://schemas.microsoft.com/intellisense/ie5">
WebForm1.aspx.cs====
using System;
using System.Collections;
using System.ComponentModel;
using System.Data;
using System.Drawing;
using System.Web;
using System.Web.SessionState;
using System.Web.UI;
using System.Web.UI.WebControls;
using System.Web.UI.HtmlControls;
namespace WebApplication1
{
///
/// Summary description for WebForm1.
///
public partial class WebForm1 : System.Web.UI.Page
{
protected void Page_Load(object sender, System.EventArgs e)
{
}
#region Web Form Designer generated code
override protected void OnInit(EventArgs e)
{
//
// CODEGEN: This call is required by the ASP.NET Web Form Designer.
//
InitializeComponent();
base.OnInit(e);
}
///
/// Required method for Designer support - do not modify
/// the contents of this method with the code editor.
///
private void InitializeComponent()
{
}
#endregion
protected void Button2_Click(object sender, System.EventArgs e)
{
//新增
ReadWriteConfig config = new ReadWriteConfig();
config.ConfigType = (int)ConfigFileType.WebConfig;
config.SetValue(this.TextBox1.Text,this.TextBox2.Text);
}
protected void Button1_Click(object sender, System.EventArgs e)
{
//删除
ReadWriteConfig config = new ReadWriteConfig();
config.ConfigType = (int)ConfigFileType.WebConfig;
config.removeElement(this.TextBox1.Text);
}
protected void Button3_Click(object sender, System.EventArgs e)
{
//修改
ReadWriteConfig config = new ReadWriteConfig();
config.ConfigType = (int)ConfigFileType.WebConfig;
config.SetValue(this.TextBox1.Text,this.TextBox2.Text);
}
}
}
PS :这里的新增 修改删除 只是对自带节点appSettings，修改，只能一个名称一个value 不灵活，因为config 虽然是xml 但不同于普通的xml不能随便加节点，要写个cs文件 并且声明，下次写个在config中自定义节点的！
虽然把程序中的重要参数放到config 里是保险的，但注意的是，config不同于其他文件，是程序配置文件，修改时主要权限！修改后 程序会重新装载编译，当前程序会话缓存会清空！程序需要重新登陆
本文作者:佚名 来源:http://hi.baidu.com/chinadaima/blog/
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