我喜欢在运行时更新
AppSettings
的 Web.config
部分中定义的键/值。但是我不想将它们实际保存到 Web.config
文件中。
我有一个巨大的 Web 应用程序,其中包含许多模块、DLL 和源代码文件。数据库配置、加密密钥、Web 服务的用户名和密码等一系列关键信息都保存在
AppSettings
文件的 web.config
部分中。最近的项目需求需要我将这些值移出 web.config
并保存在安全存储中。
我已经将这些值保护在外部位置,我可以在应用程序启动时读回它们。
这是示例代码。
Global.asax
public class Global: System.Web.HttpApplication {
protected void Application_Start(object sender, EventArgs e) {
Dictionary<string, string> secureConfig = new Dictionary<string,string>{};
// --------------------------------------------------------------------
// Here I read and decrypt keys and add them to secureConfig dictionary
// To test assume the following line is a key stored in secure sotrage.
//secureConfig = SecureConfig.LoadConfig();
secureConfig.Add("ACriticalKey","VeryCriticalValue");
// --------------------------------------------------------------------
foreach (KeyValuePair<string, string> item in secureConfig) {
ConfigurationManager.AppSettings.Add(item.Key, item.Value);
}
}
}
您可能会注意到,在多个编程团队创建的大量代码中更改对
AppSettings
的引用以从我的 secureConfig dictionary
读取其设置是不可行的,另一方面,我不应该将这些值保存在 web.config
文件中可供网络管理员和操作员、系统管理员和云管理员使用。
为了让程序员的生活更轻松,我想让他们在开发过程中将其值添加到
AppSettings
的 web.config
部分,但它们将从那里删除并稍后在部署期间放入安全存储中,但是这些值应该可供程序透明,因为它们仍在 AppSettings
部分。
问题:如何在运行时向
AppSettings
添加值,以便程序可以使用 ConfigurationManager.AppSettings["ACriticalKey"]
读取它们来获取 "VeryCriticalValue"
,而不将它们保存在 Web.Config 中?
请注意:
ConfigurationManager.AppSettings.Add(item.Key, item.Value);
给我ConfigurationErrorsException
和消息The configuration is read only.
请注意:最好某些设置应该能够像以前一样保留在
AppSettings
中
我知道这是一个老问题,但我遇到了同样的问题,我发现 Set 的工作方式与 Add 相同,并且不会抛出异常,所以只需将 Add 替换为 Set,如下所示:
ConfigurationManager.AppSettings.Set(item.Key, item.Value);
您需要利用
WebConfigurationManager.OpenWebConfiguration()
Configuration config = WebConfigurationManager.OpenWebConfiguration(HttpContext.Current.Request.ApplicationPath);
config.AppSettings.Settings.Remove("Variable");
config.AppSettings.Settings.Add("Variable", "valyue");
config.Save();
感谢 nkvu 将我引导到他的第一个链接,该链接又将我发送到Williarob的帖子“覆盖配置管理器”,我设法找到了我的问题的解决方案。
提到的博客文章介绍了如何从另一个 XML 文件读取设置,它适用于窗口应用程序和 Web 应用程序(对配置文件名和路径进行一些修改)。尽管这篇博客写于 2010 年,但它仍然可以在 .NET4 上正常运行,没有任何问题。
但是,当我要从安全设备读取我的配置时,我简化了该类,以下是如何使用 Williarob
提供的类using System;
using System.Collections.Generic;
using System.Collections.Specialized;
using System.Configuration;
using System.Configuration.Internal;
using System.Linq;
using System.Reflection;
namespace Williablog.Core.Configuration {
public sealed class ConfigSystem: IInternalConfigSystem {
private static IInternalConfigSystem clientConfigSystem;
private object appsettings;
private object connectionStrings;
/// <summary>
/// Re-initializes the ConfigurationManager, allowing us to merge in the settings from Core.Config
/// </summary>
public static void Install() {
FieldInfo[] fiStateValues = null;
Type tInitState = typeof(System.Configuration.ConfigurationManager).GetNestedType("InitState", BindingFlags.NonPublic);
if (null != tInitState) {
fiStateValues = tInitState.GetFields();
}
FieldInfo fiInit = typeof(System.Configuration.ConfigurationManager).GetField("s_initState", BindingFlags.NonPublic | BindingFlags.Static);
FieldInfo fiSystem = typeof(System.Configuration.ConfigurationManager).GetField("s_configSystem", BindingFlags.NonPublic | BindingFlags.Static);
if (fiInit != null && fiSystem != null && null != fiStateValues) {
fiInit.SetValue(null, fiStateValues[1].GetValue(null));
fiSystem.SetValue(null, null);
}
ConfigSystem confSys = new ConfigSystem();
Type configFactoryType = Type.GetType("System.Configuration.Internal.InternalConfigSettingsFactory, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", true);
IInternalConfigSettingsFactory configSettingsFactory = (IInternalConfigSettingsFactory) Activator.CreateInstance(configFactoryType, true);
configSettingsFactory.SetConfigurationSystem(confSys, false);
Type clientConfigSystemType = Type.GetType("System.Configuration.ClientConfigurationSystem, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a", true);
clientConfigSystem = (IInternalConfigSystem) Activator.CreateInstance(clientConfigSystemType, true);
}
#region IInternalConfigSystem Members
public object GetSection(string configKey) {
// get the section from the default location (web.config or app.config)
object section = clientConfigSystem.GetSection(configKey);
switch (configKey) {
case "appSettings":
// Return cached version if exists
if (this.appsettings != null) {
return this.appsettings;
}
// create a new collection because the underlying collection is read-only
var cfg = new NameValueCollection();
// If an AppSettings section exists in Web.config, read and add values from it
if (section is NameValueCollection) {
NameValueCollection localSettings = (NameValueCollection) section;
foreach (string key in localSettings) {
cfg.Add(key, localSettings[key]);
}
}
// --------------------------------------------------------------------
// Here I read and decrypt keys and add them to secureConfig dictionary
// To test assume the following line is a key stored in secure sotrage.
//secureConfig = SecureConfig.LoadConfig();
secureConfig.Add("ACriticalKey", "VeryCriticalValue");
// --------------------------------------------------------------------
foreach (KeyValuePair<string, string> item in secureConfig) {
if (cfg.AllKeys.Contains(item.Key)) {
cfg[item.Key] = item.Value;
} else {
cfg.Add(item.Key, item.Value);
}
}
// --------------------------------------------------------------------
// Cach the settings for future use
this.appsettings = cfg;
// return the merged version of the items from secure storage and appsettings
section = this.appsettings;
break;
case "connectionStrings":
// Return cached version if exists
if (this.connectionStrings != null) {
return this.connectionStrings;
}
// create a new collection because the underlying collection is read-only
ConnectionStringsSection connectionStringsSection = new ConnectionStringsSection();
// copy the existing connection strings into the new collection
foreach (ConnectionStringSettings connectionStringSetting in ((ConnectionStringsSection) section).ConnectionStrings) {
connectionStringsSection.ConnectionStrings.Add(connectionStringSetting);
}
// --------------------------------------------------------------------
// Again Load connection strings from secure storage and merge like below
// connectionStringsSection.ConnectionStrings.Add(connectionStringSetting);
// --------------------------------------------------------------------
// Cach the settings for future use
this.connectionStrings = connectionStringsSection;
// return the merged version of the items from secure storage and appsettings
section = this.connectionStrings;
break;
}
return section;
}
public void RefreshConfig(string sectionName) {
if (sectionName == "appSettings") {
this.appsettings = null;
}
if (sectionName == "connectionStrings") {
this.connectionStrings = null;
}
clientConfigSystem.RefreshConfig(sectionName);
}
public bool SupportsUserConfig { get { return clientConfigSystem.SupportsUserConfig; } }
#endregion
}
}
要安装此(或配置覆盖的原始版本),请将以下行添加到 您的全球。 Application_Start 中的类 (Global.asax.cs)
Williablog.Core.Configuration.ConfigSystem .Install();
如下:
public class Global: System.Web.HttpApplication {
//...
#region protected void Application_Start(...)
protected void Application_Start(object sender, EventArgs e) {
Williablog.Core.Configuration.ConfigSystem .Install();
//...
}
#endregion
//...
}