问一个关于config文件修改的问题

Question

如何修改下面的config文件：
<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <connectionStrings>
    <add name="OTMS.Properties.Settings.OTMSConnectionString" connectionString="Data Source=192.168.1.120;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" providerName="System.Data.SqlClient"/>
  </connectionStrings>
</configuration>
如何把connectionString="Data Source=192.168.1.120;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" 
改为 
connectionString="Data Source=192.168.1.121;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" 并且保存下来？
这个配置文件的名字叫App1.config,请高人指点

Answer 1

修改程序本身的configxml.csusing System;
using System.Configuration;
using System.Reflection;
using System.Web;
using System.Xml;public enum ConfigFileType
{
    WebConfig,
    AppConfig
}namespace ShaIyaTool.App_Code
{
    /// <summary>
    /// Summary description for ReadWriteConfig.
    /// </summary>
    public class ReadWriteConfig
    {
        public string docName = String.Empty;
        private XmlNode node = null;
        private int _configType;
        public string message;
        public int ConfigType
        {
            get { return _configType; }
            set { _configType = value; }
        }        #region GetValue
        public string GetValue(string key)
        {     //读取
            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      
                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + key + "']");
                if (addElem == null)
                {
                    message = "此key不存在！";
                    return message;
                }
                message = System.Configuration.ConfigurationSettings.AppSettings[key];
                return message;
            }
            catch
            {
                message = "操作异常，获取value值失败！";
                return message;
            }
        }
        #endregion        #region SetValue
        public string SetValue(string key, string value)
        {    //增加
            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)
                {
                    message = "此key已经存在！";
                    return message;
                }
                // 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);
                message = "添加成功！";
                return message;
            }
            catch
            {
                message = "操作异常，添加失败！";
                return message;
            }
        }        #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 string removeElement(string elementKey)
        { // 删除
            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");
                }                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + elementKey + "']");
                if (addElem == null)
                {
                    message = "此key不存在！";
                    return message;
                }
                // XPath select setting "add" element that contains this key to remove      
                node.RemoveChild(node.SelectSingleNode("//add[@key='" + elementKey + "']"));
                saveConfigDoc(cfgDoc, docName);
                message = "删除成功！";
                return message;
            }
            catch
            {
                message = "操作异常，删除失败！";
                return message;
            }
        }
        #endregion        #region modifyElement
        public string modifyElement(string elementKey, string elementValue)
        { //修改
            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      
                XmlElement addElem = (XmlElement)node.SelectSingleNode("//add[@key='" + elementKey + "']");
                if (addElem == null)
                {
                    message = "此key不存在！";
                    return message;
                }                addElem.SetAttribute("value", elementValue);
                //save it   
                saveConfigDoc(cfgDoc, docName);
                message = "修改成功！";
                return message;
            }
            catch
            {
                message = "操作异常，修改失败！";
                return message;
            }
        }
        #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
    }
}调用
//读
using ShaIyaTool.App_Code;
 ShaIyaTool.App_Code.ReadWriteConfig xml = new ShaIyaTool.App_Code.ReadWriteConfig();
            xml.ConfigType = (int)ConfigFileType.AppConfig;
            textBox1.Text = xml.GetValue("connectionString").ToString();//写 ReadWriteConfig config = new ReadWriteConfig();
                config.ConfigType = (int)ConfigFileType.AppConfig;
                config.modifyElement("connectionString", textBox1.Text);

Answer 2

错了,把 connectionString改成OTMS.Properties.Settings.OTMSConnectionString

Answer 3

高人在哪里？7楼的代码运行后的结果是：操作异常，获取value值失败！

Answer 4

那个类是给你用来修改你程序本身的config的
比如你的应用程序名为text.exe,那你的config应该是text.exe.config

Answer 5

<?xml version="1.0" encoding="utf-8" ?> 
<configuration> 
  <connectionStrings> 
    <add name="OTMS.Properties.Settings.OTMSConnectionString" connectionString="Data Source=192.168.1.120;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" providerName="System.Data.SqlClient"/> 
  </connectionStrings> 
</configuration> 
<!--如何把connectionString="Data Source=192.168.1.120;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" 
改为 
connectionString="Data Source=192.168.1.121;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123"-->
<!--修改-->
<?xml version="1.0" encoding="utf-8" ?> 
<configuration> 
  <connectionStrings> 
    <add name="OTMS.Properties.Settings.OTMSConnectionString" connectionString="Data Source=192.168.1.121;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123" providerName="System.Data.SqlClient"/> 
  </connectionStrings> 
</configuration> 
<!--然后保存就好了XML文件是可以直接修改的在打包的时候不需要打包进去-->

Answer 6

....
LZ好歹叁三角,难道还不知道直接修改...这种需求很常见啊,有些配置信息写在config里,需要程序可以去配置,比如LZ的数据库连接信息
其实LZ可以把连接字符串分开,比如
add key="server" value="127.0.0.1"
add key="account" value="sa"
add key="pwd" value="111111"
...LZ报的那个错就是因为你没这样做,我本以为你会变通考虑直接象我这样写的.
然后在程序里根据这些信息再组成连接字符串,而同时又可以用自己的程序修改这些配置信息,就用我的那个类就可以
我就是这样做的

Answer 7

//添加引用public static void SetConfig(string key,string val){
      Configuration config=ConfigurationManager.OpenExeConfiguration("");
      config.ConnectionStrings.ConnectionStrings[key].Value=val;
      config.Save();
}string name="OTMS.Properties.Settings.OTMSConnectionString"
string val="Data Source=192.168.1.121;Initial Catalog=OTMS;Persist Security Info=True;User ID=sa;Password=123"
//调用
SetConfig(name,val);
//注意每次设置完必须重新启动程序配置文件才生效//程序没编译 有小问题见谅

Answer 8

建议直接更改   应用程序text.exe.config 下的数据， 否则每次更改完都必须重新启动程序才能生效。