C#读写Config配置文件案例

一、简介

应用程序配置文件（App.config）是标准的 XML 文件，XML 标记和属性是区分大小写的。它是可以按需要更改的，开发人员可以使用配置文件来更改设置，而不必重编译应用程序。

*.exe.config配置文件样式：

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
 <connectionStrings>
 </connectionStrings>
 <appSettings>
   <add key="ServerIP" value="127.0.0.1"></add>
   <add key="DataBase" value="WarehouseDB"></add>
   <add key="user" value="sa"></add>
   <add key="password" value="sa"></add>
 </appSettings>
 <startup>
   <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.5" />
 </startup>
</configuration>

二、代码

1.配置文件读写类

using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
using System.Text.RegularExpressions;
using System.Configuration;
using System.ServiceModel;
using System.ServiceModel.Configuration;

namespace XMLDemo1
{
   public static class ConfigHelper
   {
       #region ConnectionStrings
       //依据连接串名字connectionName返回数据连接字符串  
       public static string GetConnectionStringsConfig(string connectionName)
       {
           //指定config文件读取
           string file = System.Windows.Forms.Application.ExecutablePath;
           System.Configuration.Configuration config = ConfigurationManager.OpenExeConfiguration(file);
           string connectionString =
               config.ConnectionStrings.ConnectionStrings[connectionName].ConnectionString.ToString();
           return connectionString;
       }

///<summary>
       ///更新连接字符串  
       ///</summary>
       ///<param name="newName">连接字符串名称</param>
       ///<param name="newConString">连接字符串内容</param>
       ///<param name="newProviderName">数据提供程序名称</param>
       public static void UpdateConnectionStringsConfig(string newName, string newConString, string newProviderName)
       {
           //指定config文件读取
           string file = System.Windows.Forms.Application.ExecutablePath;
           Configuration config = ConfigurationManager.OpenExeConfiguration(file);

bool exist = false; //记录该连接串是否已经存在  
           //如果要更改的连接串已经存在  
           if (config.ConnectionStrings.ConnectionStrings[newName] != null)
           {
               exist = true;
           }
           // 如果连接串已存在，首先删除它  
           if (exist)
           {
               config.ConnectionStrings.ConnectionStrings.Remove(newName);
           }
           //新建一个连接字符串实例  
           ConnectionStringSettings mySettings =
               new ConnectionStringSettings(newName, newConString, newProviderName);
           // 将新的连接串添加到配置文件中.  
           config.ConnectionStrings.ConnectionStrings.Add(mySettings);
           // 保存对配置文件所作的更改  
           config.Save(ConfigurationSaveMode.Modified);
           // 强制重新载入配置文件的ConnectionStrings配置节  
           ConfigurationManager.RefreshSection("ConnectionStrings");
       }

#endregion

#region appSettings
       ///<summary>
       ///返回*.exe.config文件中appSettings配置节的value项  
       ///</summary>
       ///<param name="strKey"></param>
       ///<returns></returns>
       public static string GetAppConfig(string strKey)
       {
           //D:\Winform\xml文档操作\XMLDemo1\bin\Debug\XMLDemo1.EXE
           string file = System.Windows.Forms.Application.ExecutablePath;
           Configuration config = ConfigurationManager.OpenExeConfiguration(file);
           foreach (string key in config.AppSettings.Settings.AllKeys)
           {
               if (key == strKey)
               {
                   return config.AppSettings.Settings[strKey].Value.ToString();
               }
           }
           return null;
       }

///<summary>  
       ///在*.exe.config文件中appSettings配置节增加一对键值对  
       ///</summary>  
       ///<param name="newKey"></param>  
       ///<param name="newValue"></param>  
       public static void UpdateAppConfig(string newKey, string newValue)
       {
           string file = System.Windows.Forms.Application.ExecutablePath;
           Configuration config = ConfigurationManager.OpenExeConfiguration(file);
           bool exist = false;
           foreach (string key in config.AppSettings.Settings.AllKeys)
           {
               if (key == newKey)
               {
                   exist = true;
               }
           }
           if (exist)
           {
               config.AppSettings.Settings.Remove(newKey);
           }
           config.AppSettings.Settings.Add(newKey, newValue);
           config.Save(ConfigurationSaveMode.Modified);
           ConfigurationManager.RefreshSection("appSettings");
       }
       #endregion

#region
       // 修改system.serviceModel下所有服务终结点的IP地址
       public static void UpdateServiceModelConfig(string configPath, string serverIP)
       {
           Configuration config = ConfigurationManager.OpenExeConfiguration(configPath);
           ConfigurationSectionGroup sec = config.SectionGroups["system.serviceModel"];
           ServiceModelSectionGroup serviceModelSectionGroup = sec as ServiceModelSectionGroup;
           ClientSection clientSection = serviceModelSectionGroup.Client;
           foreach (ChannelEndpointElement item in clientSection.Endpoints)
           {
               string pattern = @"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b";
               string address = item.Address.ToString();
               string replacement = string.Format("{0}", serverIP);
               address = Regex.Replace(address, pattern, replacement);
               item.Address = new Uri(address);
           }

config.Save(ConfigurationSaveMode.Modified);
           ConfigurationManager.RefreshSection("system.serviceModel");
       }

// 修改applicationSettings中App.Properties.Settings中服务的IP地址
       public static void UpdateConfig(string configPath, string serverIP)
       {
           Configuration config = ConfigurationManager.OpenExeConfiguration(configPath);
           ConfigurationSectionGroup sec = config.SectionGroups["applicationSettings"];
           ConfigurationSection configSection = sec.Sections["DataService.Properties.Settings"];
           ClientSettingsSection clientSettingsSection = configSection as ClientSettingsSection;
           if (clientSettingsSection != null)
           {
               SettingElement element1 = clientSettingsSection.Settings.Get("DataService_SystemManagerWS_SystemManagerWS");
               if (element1 != null)
               {
                   clientSettingsSection.Settings.Remove(element1);
                   string oldValue = element1.Value.ValueXml.InnerXml;
                   element1.Value.ValueXml.InnerXml = GetNewIP(oldValue, serverIP);
                   clientSettingsSection.Settings.Add(element1);
               }

SettingElement element2 = clientSettingsSection.Settings.Get("DataService_EquipManagerWS_EquipManagerWS");
               if (element2 != null)
               {
                   clientSettingsSection.Settings.Remove(element2);
                   string oldValue = element2.Value.ValueXml.InnerXml;
                   element2.Value.ValueXml.InnerXml = GetNewIP(oldValue, serverIP);
                   clientSettingsSection.Settings.Add(element2);
               }
           }
           config.Save(ConfigurationSaveMode.Modified);
           ConfigurationManager.RefreshSection("applicationSettings");
       }

private static string GetNewIP(string oldValue, string serverIP)
       {
           string pattern = @"\b\d{1,3}\.\d{1,3}\.\d{1,3}\.\d{1,3}\b";
           string replacement = string.Format("{0}", serverIP);
           string newvalue = Regex.Replace(oldValue, pattern, replacement);
           return newvalue;
       }
       #endregion
   }
}

2.Main 函数

namespace XMLDemo1
{
   class Program
   {
       static void Main(string[] args)
       {
           try
           {
               //D:\Winform\xml文档操作\XMLDemo1\bin\Debug\XMLDemo1.EXE
               //string file0 = System.Windows.Forms.Application.ExecutablePath;
               //D:\Winform\xml文档操作\XMLDemo1\bin\Debug\XMLDemo1.EXE.config
               //string file = System.Windows.Forms.Application.ExecutablePath + ".config";
               //D:\Winform\xml文档操作\XMLDemo1\bin\Debug\XMLDemo1.vshost.exe.Config
               //string file1 = AppDomain.CurrentDomain.SetupInformation.ConfigurationFile;

string serverIP = ConfigHelper.GetAppConfig("ServerIP");
               string db = ConfigHelper.GetAppConfig("DataBase");
               string user = ConfigHelper.GetAppConfig("user");
               string password = ConfigHelper.GetAppConfig("password");

Console.WriteLine(serverIP);
               Console.WriteLine(db);
               Console.WriteLine(user);
               Console.WriteLine(password);

ConfigHelper.UpdateAppConfig("ServerIP", "192.168.0.1");
               string newIP = ConfigHelper.GetAppConfig("ServerIP");
               Console.WriteLine(newIP);
               ConfigHelper.UpdateConnectionStringsConfig("connstr4", ".......", "System.Data.Sqlclient");

Console.ReadKey();
           }
           catch (Exception ex)
           {
               Console.WriteLine(ex.Message);
           }
       }
   }
}

来源：https://www.cnblogs.com/wml-it/p/14813617.html