webforms - Google reCAPTCHA 2 ("noCAPTCHA") does not get reapplied when using ASP.NET Web-Form UpdatePanel -

google recaptcha 2 ("nocaptcha") not reapplied when using updatepanel

i not using old asp.net recaptcha control.

here code running.

<asp:scriptmanager id="scriptmanager1" runat="server" />     <asp:updatepanel id="googlecaptchaupdatepanel" runat="server" updatemode="always" >         <contenttemplate>         <div class="googlecaptchawrapper">             <div class="g-recaptcha" data-sitekey="<%= getcaptchapublickey() %>"></div>             <asp:label id="captchaerror" cssclass="captchaerror" runat="server" forecolor="red" visible="false" />         </div>          <div class="smallcontentrow" style="margin-top: 10px; margin-left: auto; margin-right: auto; width: 100%; text-align: center;">             <asp:linkbutton id="btnsubmit" runat="server" cssclass="mybtn" causesvalidation="false" text="submit" tabindex="9" tooltip="click submit info"/>             <asp:linkbutton id="btncancel" runat="server" causesvalidation="false" cssclass="mybtn" text="cancel" tabindex="10" tooltip="click cancel info "/>         </div>     </contenttemplate> </asp:updatepanel> 

when click submit button, captcha not re-applied screen.

i've attempted resolve issue various javascript solutions have been posted, seem older version of google's recaptcha.

i figured out how.

i ended explicitly rendering new recaptcha, or recaptcha 2.

in site masterpage, declared recaptcha js scripts as:

<script src="https://www.google.com/recaptcha/api.js?onload=onloadcallback&render=explicit" async defer ></script> 

in webpage, created placeholder captcha this:

<div class="mycaptchawrapper">     <div id="mycaptcha" class="g-recaptcha"></div>     <asp:label id="errormessage" cssclass="stylederrors" runat="server" forecolor="red" visible="false" /> </div> 

then, in captcha js:

function loadcaptcha() {     grecaptcha.render('mycaptcha', {         'sitekey': mysitekey,         'theme': 'clear',         'callback': myclientresponsecallback     }); } 

and call secure web service in myclientresponsecallback server-side processing need to.

doing this, can handle action when user clicks on 'apply' in recaptcha, , can handle checking if captcha has been answered through server-side processing in asp.net post-back.