How do I make an extension xsd for the web/app.config schema?

Question

How do I make a schema for custom config sections? I tried making one, but when I used it, it said the only expected element was what I had in that schema, and complained about the standard web.config stuff, even though I was still using the normal DotNetConfig.xsd file too.

Answer 1

This question I found isn't duplicate, but the solution will solve your problem:

How to fix Error: "Could not find schema information for the attribute/element" by creating schema

The trick is to get the "Properties" of the app.config editor, and set the Schemas value:

• Right Click -> Properties anywhere in the XML file editor, or just hit F4 while it is in focus
• In that dialog, add a local or absolute reference to a schema file

My app.config file's properties window/gadget looks like this:

Here's an example I just got working (I'm toying around with Ninject and NLog). The elements and attributes under the nlog section show up correctly in Intellisense, and I get squiggly lines if I violate the schema.

<?xml version="1.0"?>
<configuration>
  <configSections>
    <section name="nlog" type="NLog.Config.ConfigSectionHandler, NLog" />
  </configSections>
  <nlog xmlns="http://www.nlog-project.org/schemas/NLog.xsd"
        xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance">
    <targets>
      <target name="eventLog" xsi:type="EventLog" log="Application"
              category="TestService" />
      <target name="file" xsi:type="File"
              layout="${longdate}|${stacktrace}|${message}"
              fileName="${logger}.txt" />
    </targets>
    <rules>
      <logger name="*" minlevel="Info" writeTo="eventLog" />
      <logger name="*" minlevel="Debug" writeTo="file"/>
    </rules>
  </nlog>
  <startup>
    <supportedRuntime version="v4.0" sku=".NETFramework,Version=v4.0" />
  </startup>
</configuration>

My schema file is in my project root, right next to app.config, and called NLog.xsd. I simply saved it from here:

• http://nlog-project.org/schemas/NLog.xsd