配置文件——WebApp.config文件读取和修改

using System;
using System.Collections.Generic;
using System.Configuration;
using System.Linq;
using System.Net.Mime;
using System.Text;
using System.Threading.Tasks;
using System.Web;
using System.Xml;

namespace Infrastructure
{
public class WebConfigHelper
{
private Configuration _config;
private readonly string _configPath;
private readonly ConfigType _configType;

/// <summary>
/// 对应的配置文件
/// </summary>
public Configuration Configuration
{
get { return _config; }
set { _config = value; }
}

/// <summary>
/// 构造函数
/// </summary>
public WebConfigHelper()
{
_configPath = HttpContext.Current.Request.ApplicationPath;
Initialize();
}

/// <summary>
/// 构造函数
/// </summary>
/// <param name="configPath">.config文件的位置</param>
/// <param name="configType">.config文件的类型，只能是网站配置文件或者应用程序配置文件</param>
public WebConfigHelper(string configPath, ConfigType configType)
{
this._configPath = configPath;
this._configType = configType;
Initialize();
}

//实例化configuration,根据配置文件类型的不同，分别采取了不同的实例化方法
private void Initialize()
{
//如果是WinForm应用程序的配置文件

if (_configType == ConfigType.ExeConfig)
{
_config = ConfigurationManager.OpenExeConfiguration(_configPath);
}
else //WebForm的配置文件
{
_config = System.Web.Configuration.WebConfigurationManager.OpenWebConfiguration(_configPath);
}
}

public string GetValueByKey(string key)
{
return ConfigurationManager.AppSettings[key];
}

/// <summary>
/// 添加应用程序配置节点，如果已经存在此节点，则会修改该节点的值
/// </summary>
/// <param name="key">节点名称</param>
/// <param name="value">节点值</param>
public void AddAppSetting(string key, string value)
{
var appSetting = (AppSettingsSection)_config.GetSection("appSettings");
if (appSetting.Settings[key] == null) //如果不存在此节点，则添加
{
appSetting.Settings.Add(key, value);
}
else //如果存在此节点，则修改
{
ModifyAppSetting(key, value);
}
}

/// <summary>
/// 修改应用程序配置节点，如果不存在此节点，则会添加此节点及对应的值
/// </summary>
/// <param name="key">节点名称</param>
/// <param name="newValue">节点值</param>
public void ModifyAppSetting(string key, string newValue)
{
var appSetting = (AppSettingsSection)_config.GetSection("appSettings");
if (appSetting.Settings[key] != null) //如果存在此节点，则修改
{
appSetting.Settings[key].Value = newValue;
}
else //如果不存在此节点，则添加
{
AddAppSetting(key, newValue);
}
}

/// <summary>
/// 添加数据库连接字符串节点，如果已经存在此节点，则会修改该节点的值
/// </summary>
/// <param name="key">节点名称</param>
/// <param name="connectionString">节点值</param>
public void AddConnectionString(string key, string connectionString)
{
var connectionSetting = (ConnectionStringsSection)_config.GetSection("connectionStrings");
if (connectionSetting.ConnectionStrings[key] == null) //如果不存在此节点，则添加
{
var connectionStringSettings = new ConnectionStringSettings(key, connectionString);
connectionSetting.ConnectionStrings.Add(connectionStringSettings);
}
else //如果存在此节点，则修改
{
ModifyConnectionString(key, connectionString);
}
}

/// <summary>
/// 修改数据库连接字符串节点，如果不存在此节点，则会添加此节点及对应的值
/// </summary>
/// <param name="key">节点名称</param>
/// <param name="connectionString">节点值</param>
public void ModifyConnectionString(string key, string connectionString)
{
var connectionSetting = (ConnectionStringsSection)_config.GetSection("connectionStrings");
if (connectionSetting.ConnectionStrings[key] != null) //如果存在此节点，则修改
{
connectionSetting.ConnectionStrings[key].ConnectionString = connectionString;
}
else //如果不存在此节点，则添加
{
AddConnectionString(key, connectionString);
}
}

/// <summary>
/// 保存所作的修改
/// </summary>
public void Save()
{
_config.Save();
}
}
public enum ConfigType
{
/// <summary>
/// asp.net网站的config文件
/// </summary>
WebConfig = 1,
/// <summary>
/// Windows应用程序的config文件
/// </summary>
ExeConfig = 2
}
}