App.config中

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="example" type="CustomConfig.ExampleSection,CustomConfig" />
  </configSections>
  <example version="A sample string value." />
  <appSettings>
    <add key="version_string" value="1.01" />
  </appSettings>
</configuration>

但是,当我更改App.config文件时,我的自定义部分将从configSource中提到的外部配置文件中读取,Visual Studio给出了一个错误

The format of a configSource file must be an element containing the name
of the section.

这是App.config和example.config文件

更改了App.config

<?xml version="1.0" encoding="utf-8" ?>
<configuration>
  <configSections>
    <section name="example" type="CustomConfig.ExampleSection,CustomConfig" />
  </configSections>
  <example configSource="example.config" />
  <appSettings>
    <add key="version_string" value="1.01" />
  </appSettings>
</configuration>

example.config

<?xml version="1.0"?>
<example>
    <add key="version" value="blahblah" />
</example>