title: can I analyze a parameter sent from a tag helper?
body: <p>I'm working with asp net core 3.1 and in my mvc webapplication I call a razorpage with a tag helper:</p>
  <pre><code>&lt;button type=&quot;submit&quot; class=&quot;btn btn-light&quot; asp-area=&quot;Identity&quot; asp-page=&quot;/Account/Register&quot; asp-route-id=&quot;pf&quot;&gt;Register&lt;/button&gt;
  </code></pre>
  <p>when &quot;arrive&quot; in RegisterModel I'd like to analyze the parameter &quot;pf&quot; but I don't understand how. I find a method</p>
  <pre><code>OnGetAsync(string returnUrl = null)
  </code></pre>
  <p>and I change it so:</p>
  <pre><code>OnGetAsync(string id, string returnUrl = null)
  </code></pre>
  <p>but the id parameter is always null. Any assistance are appreciated very much.</p>