sub appsettings in the appsetting node c#

Question

I am using the app.config file that is created with a console application and I can read the val1 of the key1 using the ConfigurationSettings.AppSettings["key1"].ToString()

<configuration>  
    <startup> 
        <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
    </startup>  
    <appSettings>
        <add key="key1" value="val1" />
        <add key="key2" value="val2" />  
    </appSettings> 
</configuration>

but I have too many keys and values that I want to make them categorized.

I found something that is difficult to use in my application since I want to access the keys in a similar way to the above one

Showing all nodes and can't read a node without getting all the nodes

for example what I want to do:

<appSettings>
    <Section1>
        <add key="key1" value="val1" />
    </Section1>
    <Section2>
        <add key="key1" value="val1" />
    <Section2>
</appSettings>

and if there is a way to access it using ConfigurationSettings.AppSettings["Section1"].["key1"].ToString()

Answer 1

You can add custom sections in app.config without writing additional code. All you have to do is "declaring" new section in configSections node like that

<configSections>
      <section name="genericAppSettings" type="System.Configuration.AppSettingsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
  </configSections>

and then you can define this section filling it with keys and values:

  <genericAppSettings>
      <add key="testkey" value="generic" />
      <add key="another" value="testvalue" />
  </genericAppSettings>

To get value of a key from this section you have to add System.Configuration dll as reference to your project, add using and use GetSection method. Example:

using System.Collections.Specialized;
using System.Configuration;

namespace ConsoleApplication1
{
    class Program
    {
        static void Main(string[] args)
        {
            NameValueCollection test = (NameValueCollection)ConfigurationManager.GetSection("genericAppSettings");

            string a = test["another"];
        }
    }
}

Nice thing is that you can easily make groups of sections if you need this:

<configSections>
    <sectionGroup name="customAppSettingsGroup">
      <section name="genericAppSettings" type="System.Configuration.AppSettingsSection, System.Configuration, Version=2.0.0.0, Culture=neutral, PublicKeyToken=b03f5f7f11d50a3a" />
 // another sections
    </sectionGroup>
</configSections>

  <customAppSettingsGroup>
    <genericAppSettings>
      <add key="testkey" value="generic" />
      <add key="another" value="testvalue" />
    </genericAppSettings>
    // another sections
  </customAppSettingsGroup>

If you use groups, to access sections you have to access them using {group name}/{section name} format:

NameValueCollection test = (NameValueCollection)ConfigurationManager.GetSection("customAppSettingsGroup/genericAppSettings");

Answer 2

AFAIK you can implement a custom section outside of the appsettings. For example, frameworks like Autofac and SpecFlow use these kind of sessions to support their own configuration schema. You can take a look on this MSDN article to understand how to do that. Hope that helps.