通过Web.config中的configSections配置自己系统的全局常量

随着系统的庞大，你的全局信息保存在appsitting里可能会比较乱，不如为模块写个自定义的全局常量吧

首先在Web.Config文件中的代码可能是这样：
<configuration>
<configSections>
<section name="MyConfig" type="My.Core.Configuration.MyConfig, My.Core" requirePermission="false" />
</configSections>

而YipongConfig可能是这样：
public object Create(object parent, object configContext, XmlNode section)
{
var config = new YipongConfig();
var dynamicDiscoveryNode = section.SelectSingleNode("DynamicDiscovery");
if (dynamicDiscoveryNode != null && dynamicDiscoveryNode.Attributes != null)
{
var attribute = dynamicDiscoveryNode.Attributes["Enabled"];
if (attribute != null)
config.DynamicDiscovery = Convert.ToBoolean(attribute.Value);
}

var engineNode = section.SelectSingleNode("Engine");
if (engineNode != null && engineNode.Attributes != null)
{
var attribute = engineNode.Attributes["Type"];
if (attribute != null)
config.EngineType = attribute.Value;
}

var startupNode = section.SelectSingleNode("Startup");
if (startupNode != null && startupNode.Attributes != null)
{
var attribute = startupNode.Attributes["IgnoreStartupTasks"];
if (attribute != null)
config.IgnoreStartupTasks = Convert.ToBoolean(attribute.Value);
}

var themeNode = section.SelectSingleNode("Themes");
if (themeNode != null && themeNode.Attributes != null)
{
var attribute = themeNode.Attributes["basePath"];
if (attribute != null)
config.ThemeBasePath = attribute.Value;
}

var userAgentStringsNode = section.SelectSingleNode("UserAgentStrings");
if (userAgentStringsNode != null && userAgentStringsNode.Attributes != null)
{
var attribute = userAgentStringsNode.Attributes["databasePath"];
if (attribute != null)
config.UserAgentStringsPath = attribute.Value;
}

return config;
}

/// <summary>
/// In addition to configured assemblies examine and load assemblies in the bin directory.
/// </summary>
public bool DynamicDiscovery { get; private set; }

/// <summary>
/// A custom <see cref="IEngine"/> to manage the application instead of the default.
/// </summary>
public string EngineType { get; private set; }

/// <summary>
/// Specifices where the themes will be stored (~/Themes/)
/// </summary>
public string ThemeBasePath { get; private set; }

/// <summary>
/// Indicates whether we should ignore startup tasks
/// </summary>
public bool IgnoreStartupTasks { get; private set; }

/// <summary>
/// Path to database with user agent strings
/// </summary>
public string UserAgentStringsPath { get; private set; }
}

调用就可以这样：
string myWebSiteName = ((NameValueCollection)ConfigurationSettings.GetConfig("SiteConfig"))["SiteName"];