Enabling Intellisense for Custom Sections in .config Files

Question

When editing .NET config files (app.config, web.config, etc) in Visual Studio, I get Visual Studio's intellisense to guide me when choosing my application's settings. If I add a custom configuration section, how can I enable intellisense for my custom settings? I'm sure there must be an easy answer to this, but a cursory Google search didn't give me any help.

Thanks!

Answer 1

As the other answers say, you need to provide an XML Schema document for your custom configuration section. There's no need to add the .xsd schema file to some global directory; you can reference it directly from your custom section in the App.config file:

<configuration>

  <!-- make the custom section known to .NET's configuration manager -->
  <configSections>
    <section name="customSection" type="..." />
  </configSections>

  <!-- your custom section -->
  <customSection xmlns="http://tempuri.org/customSection.xsd"
                 xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
                 xsi:noNamespaceSchemaLocation="customSection.xsd">
    ...
  </customSection>

<configuration>

The xmlns attribute is merely there to set a default namespace, so that you don't need to set it on your customSection element and all of its child elements. (However, do not place the xmlns attribute on the <configuration> element!)

The customSection.xsd contains the schema that will be used by IntelliSense, for example:

<xs:schema id="customSectionSchema"
           targetNamespace="http://tempuri.org/customSection.xsd"
           elementFormDefault="qualified"
           xmlns="http://tempuri.org/customSection.xsd"
           xmlns:mstns="http://tempuri.org/customSection.xsd"
           xmlns:xs="http://www.w3.org/2001/XMLSchema">
  <xs:element name="customSection">
    ...
  </xs:element>
</xs:schema>