title: I want autopostback on dropdownlist on Razor page not MVC
body: <p>I want autopostback on dropdownlist on Razor page not MVC
  I have this code but it not working, the intention is to call what has been select immediately for another process.</p>
  <pre><code>&lt;select id=&quot;ddlDList&quot; class=&quot;form-control&quot; name=&quot;PredefineID&quot; asp-items=&quot;@Model.ListModes&quot; new { onchange = &quot;DoPostBack();&quot; }&quot;&gt;
  
  &lt;option value=&quot;0&quot;&gt;Please select&lt;/option&gt;
   &lt;/select&gt;
  </code></pre>
  <p>.......</p>
  <pre><code>public string DoPostBack()
      {
        …..  
  
          return listdefine;
      }
  </code></pre>