How to: Create Custom Configuration Sections Using ConfigurationSection

https://msdn.microsoft.com/en-us/library/2tw134k3.aspx

You can extend ASP.NET configuration settings with XML configuration elements of your own.

To do this, you create a custom configuration section handler.

The handler must be a .NET Framework class that inherits from the System.Configuration.ConfigurationSection class.

The section handler interprets解释 and processes the settings that are defined in XML configuration elements in a specific section of a Web.config file.

You can read and write these settings through the handler's properties.

To create a custom configuration section handler

1. Create a public class that inherits from the System.Configuration.ConfigurationSection class.

2. Add code to define the section's attributes and elements.

The following example shows how to create a handler for a custom configuration section named "PageAppearance."

The section has a RemoteOnly attribute and Font and Color elements.

The code shows how to use string, integer, and Boolean attributes.

It also shows how to use string and integer validators验证器 for those attributes. (The Boolean attribute is automatically validated经过验证的.)

The validators check the format of the configuration markup at run time and throw exceptions if the values provided for the custom attributes do not meet the specified criteria.

This example uses the declarative model.

A configuration section handler can also be implemented programmatically.

For an example, see Classes Used to Create Custom Section Handlers and the System.Configuration.ConfigurationSection class overview.

To add a custom section handler to an ASP.NET configuration file

1.In the Web.config file, add a sectionGroup element and a section element inside the configSections element, as shown in the following example.

The declaration associates the custom section handler with the section name.

Note:Nesting a section element in a sectionGroup is optional, but we recommend doing this to help organize configuration data.

<configuration>
<!-- Configuration section-handler declaration area. -->
  <configSections>
    <sectionGroup name="pageAppearanceGroup">
      <section
        name="pageAppearance"
        type="Samples.AspNet.PageAppearanceSection"
        allowLocation="true"
        allowDefinition="Everywhere"
      />
    </sectionGroup>
      <!-- Other <section> and <sectionGroup> elements. -->
  </configSections>

  <!-- Configuration section settings area. -->

</configuration>

You can add the section-handler declaration in a different configuration file than the one where you add the custom configuration elements,

providing that the configuration file where the section handler is declared is higher in the configuration file hierarchy.

If you add the section handler declaration to a configuration file that is outside of your application, you must do the following:

• Include the assembly that defines the section in the same directory as the Web.config file.

• Ensure that the type attribute of the section element matches the manifest of the assembly (ensure that you specify both the correct namespace and type name).

If either of these conditions is not fulfilled, a configuration error will be thrown.

For more information, see ASP.NET Configuration File Hierarchy and Inheritance.

2.Add custom configuration elements in the configuration section settings area of the Web.config file, as shown in the following example:

<configuration>

<!-- Configuration section-handler declaration area. -->

  <!-- Configuration section settings area. -->
  <pageAppearanceGroup>
    <pageAppearance remoteOnly="true">
      <font name="TimesNewRoman" size="18"/>
      <color background="000000" foreground="FFFFFF"/>
    </pageAppearance>
  </pageAppearanceGroup>

  <!-- Other configuration settings, such as system.web -->

</configuration>

To programmatically access custom configuration data

Get an instance of the custom configuration object and use the GetSection method or the GetSection method to populate it.

The following example shows an ASP.NET Web page that works with the previous examples to enumerate the attributes and child elements of the custom configuration section.

<%@ Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
  protected void Page_Load(object sender, EventArgs e)
  {
    Samples.AspNet.PageAppearanceSection config =
        (Samples.AspNet.PageAppearanceSection)System.Configuration.ConfigurationManager.GetSection(
        "pageAppearanceGroup/pageAppearance");

    Response.Write("<h2>Settings in the PageAppearance Section:</h2>");
    Response.Write(string.Format("RemoteOnly: {0}<br>",
        config.RemoteOnly));
    Response.Write(string.Format("Font name and size: {0} {1}<br>",
        config.Font.Name, config.Font.Size));
    Response.Write(
        string.Format("Background and foreground color: {0} {1}<br>",
        config.Color.Background, config.Color.Foreground));
  }
</script>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
  <title>Custom Configuration Section Example</title>
</head>
<body>
  <form id="form1" runat="server">
  <div>
    <h1>
  </div>
  </form>
</body>
</html>

class derived from ConfigurationSection Class

https://docs.microsoft.com/en-us/dotnet/api/system.configuration.configurationsection?view=netframework-4.7.2

System.Configuration.AppSettingsSection

System.Configuration.ClientSettingsSection

System.Configuration.ConfigurationBuildersSection

System.Configuration.ConnectionStringsSection

System.Configuration.DefaultSection

System.Configuration.IgnoreSection

System.Configuration.ProtectedConfigurationSection

System.Configuration.UriSection

System.Data.Services.Configuration.DataServicesFeaturesSection

System.Drawing.Configuration.SystemDrawingSection

System.IdentityModel.Configuration.SystemIdentityModelSection

System.IdentityModel.Services.Configuration.SystemIdentityModelServicesSection

System.Net.Configuration.AuthenticationModulesSection

System.Net.Configuration.ConnectionManagementSection

System.Net.Configuration.DefaultProxySection

System.Net.Configuration.RequestCachingSection

System.Net.Configuration.SettingsSection

System.Net.Configuration.SmtpSection

System.Net.Configuration.WebRequestModulesSection

System.Runtime.Caching.Configuration.MemoryCacheSection

System.Runtime.Serialization.Configuration.DataContractSerializerSection

System.Runtime.Serialization.Configuration.NetDataContractSerializerSection

System.ServiceModel.Activation.Configuration.DiagnosticSection

System.ServiceModel.Activation.Configuration.NetPipeSection

System.ServiceModel.Activation.Configuration.NetTcpSection

System.ServiceModel.Activities.Configuration.WorkflowHostingOptionsSection

System.ServiceModel.Activities.Tracking.Configuration.TrackingSection

System.ServiceModel.Configuration.BehaviorsSection

System.ServiceModel.Configuration.BindingsSection

System.ServiceModel.Configuration.ClientSection

System.ServiceModel.Configuration.ComContractsSection

System.ServiceModel.Configuration.CommonBehaviorsSection

System.ServiceModel.Configuration.DiagnosticSection

System.ServiceModel.Configuration.ExtensionsSection

System.ServiceModel.Configuration.ProtocolMappingSection

System.ServiceModel.Configuration.ServiceHostingEnvironmentSection

System.ServiceModel.Configuration.ServicesSection

System.ServiceModel.Configuration.StandardEndpointsSection

System.ServiceModel.Routing.Configuration.RoutingSection

System.Transactions.Configuration.DefaultSettingsSection

System.Transactions.Configuration.MachineSettingsSection

System.Web.Configuration.AnonymousIdentificationSection

System.Web.Configuration.AuthenticationSection

System.Web.Configuration.AuthorizationSection

System.Web.Configuration.CacheSection

System.Web.Configuration.ClientTargetSection

System.Web.Configuration.CompilationSection

System.Web.Configuration.CustomErrorsSection

System.Web.Configuration.DeploymentSection

System.Web.Configuration.FullTrustAssembliesSection

System.Web.Configuration.GlobalizationSection

System.Web.Configuration.HealthMonitoringSection

System.Web.Configuration.HostingEnvironmentSection

System.Web.Configuration.HttpCookiesSection

System.Web.Configuration.HttpHandlersSection

System.Web.Configuration.HttpModulesSection

System.Web.Configuration.HttpRuntimeSection

System.Web.Configuration.IdentitySection

System.Web.Configuration.MachineKeySection

System.Web.Configuration.MembershipSection

System.Web.Configuration.OutputCacheSection

System.Web.Configuration.OutputCacheSettingsSection

System.Web.Configuration.PagesSection

System.Web.Configuration.PartialTrustVisibleAssembliesSection

System.Web.Configuration.ProcessModelSection

System.Web.Configuration.ProfileSection

System.Web.Configuration.ProtocolsSection

System.Web.Configuration.RoleManagerSection

System.Web.Configuration.ScriptingAuthenticationServiceSection

System.Web.Configuration.ScriptingJsonSerializationSection

System.Web.Configuration.ScriptingProfileServiceSection

System.Web.Configuration.ScriptingRoleServiceSection

System.Web.Configuration.ScriptingScriptResourceHandlerSection

System.Web.Configuration.SecurityPolicySection

System.Web.Configuration.SessionPageStateSection

System.Web.Configuration.SessionStateSection

System.Web.Configuration.SiteMapSection

System.Web.Configuration.SqlCacheDependencySection

System.Web.Configuration.TraceSection

System.Web.Configuration.TrustSection

System.Web.Configuration.UrlMappingsSection

System.Web.Configuration.WebControlsSection

System.Web.Configuration.WebPartsSection

System.Web.Configuration.XhtmlConformanceSection

System.Web.Mobile.DeviceFiltersSection

System.Web.Services.Configuration.WebServicesSection

System.Web.UI.MobileControls.MobileControlsSection

System.Windows.Forms.WindowsFormsSection

System.Workflow.Activities.ExternalDataExchangeServiceSection

System.Workflow.Activities.Configuration.ActiveDirectoryRoleFactoryConfiguration

System.Workflow.Runtime.Configuration.WorkflowRuntimeSection

System.Xml.Serialization.Configuration.DateTimeSerializationSection

System.Xml.Serialization.Configuration.SchemaImporterExtensionsSection

System.Xml.Serialization.Configuration.XmlSerializerSection

<runtime> Element

https://docs.microsoft.com/en-us/dotnet/framework/configure-apps/file-schema/runtime/runtime-element

How to programatically modify assemblyBinding in app.config?

https://stackoverflow.com/questions/809262/how-to-programatically-modify-assemblybinding-in-app-config

I found what I needed. The XmlNamespaceManager is required as the assemblyBinding node contains the xmlns attribute. I modified the code to use this and it works:

 private void SetRuntimeBinding(string path, string value)
    {
        XmlDocument doc = new XmlDocument();

        try
        {
            doc.Load(Path.Combine(path, "MyApp.exe.config"));
        }
        catch (FileNotFoundException)
        {
            return;
        }

        XmlNamespaceManager manager = new XmlNamespaceManager(doc.NameTable);
        manager.AddNamespace("bindings", "urn:schemas-microsoft-com:asm.v1");

        XmlNode root = doc.DocumentElement;

        XmlNode node = root.SelectSingleNode("//bindings:bindingRedirect", manager);

        if (node == null)
        {
            throw (new Exception("Invalid Configuration File"));
        }

        node = node.SelectSingleNode("@newVersion");

        if (node == null)
        {
            throw (new Exception("Invalid Configuration File"));
        }

        node.Value = value;

        doc.Save(Path.Combine(path, "MyApp.exe.config"));
    }