title: How to write an URI string in App.Config
body: <p>I am making a <code>Windows Service</code>. The <code>Service</code> has to donwload something every night, and therefor I want to place the URI in the App.Config in case I later need to change it. </p>
  
  <p>I want to write an URI in my App.Config. What makes it invalid and how should i approach this?</p>
  
  <pre><code>&lt;appSettings&gt;
      &lt;add key="fooUriString" 
           value="https://foo.bar.baz/download/DownloadStream?id=5486cfb8c50c9f9a2c1bc43daf7ddeed&amp;login=null&amp;password=null"/&gt;
  &lt;/appSettings&gt;
  </code></pre>
  
  <p>My errors:</p>
  
  <pre><code>- Entity 'login' not defined
  - Expecting ';'
  - Entity 'password' not defined
  - Application Configuration file "App.config" is invalid. An error occurred
  </code></pre>