title: Xamarin Community Toolkit InputValidation connect with button
body: <p>I have a simple form where user add email:</p>
  <pre><code>                       &lt;Entry Placeholder=&quot;Email&quot; Text=&quot;{Binding Email}&quot;&gt;
                              &lt;Entry.Behaviors&gt;
                                  &lt;xct:MultiValidationBehavior &gt;
                                      &lt;xct:EmailValidationBehavior  Flags=&quot;ValidateOnUnfocusing&quot;/&gt;
                                  &lt;/xct:MultiValidationBehavior&gt;
                              &lt;/Entry.Behaviors&gt;
                          &lt;/Entry&gt;
  </code></pre>
  <p>And have a button:</p>
  <pre><code>     &lt;Button Text=&quot;Send&quot; Command=&quot;{Binding LoadSendRegistrationCommand}&quot; TextColor=&quot;#07987f&quot;  BackgroundColor=&quot;#eeeeee&quot;  Margin=&quot;0,10,0,10&quot;&gt;&lt;/Button&gt;
  </code></pre>
  <p>When click on button how to check and return message if email is not valid?</p>