title: iOS doesn't open Zoom app using Xamarin Essentials Launcher.OpenAsync
body: <p>My xamarin.forms app is meant to join a Zoom meeting on a mobile device using <code>Launcher.OpenAsync()</code> with a uri scheme of the form &quot;zoomus://zoom.us/join?confno=1234567890&amp;pwd=123456&quot;.</p>
  <p>This works fine on Android, but on iOS it doesn't seem to do anything at all. I call <code>Launcher.CanOpenAsync()</code> beforehand, and that returns true, so the uri should be OK. The Zoom app is already installed. In info.plist I have added zoomus (and zoom) to <code>LSApplicationQueriesSchemes</code>.</p>
  <p>My code looks like this:</p>
  <pre class="lang-c# prettyprint-override"><code>private void RunZoomAsync()
  {
      Task zoomTask = Task.Run(async () =&gt;
      {
          if (await Launcher.CanOpenAsync(selectedMedia.Uri))
          {
              Message = &quot;Launching Zoom&quot;;
              await Launcher.OpenAsync(selectedMedia.Uri).ConfigureAwait(false);
          }
          else
          {
              Message = &quot;Zoom not found. You must install Zoom from your App Store&quot;;
          }
      });
  }
  </code></pre>
  <p>I see the message on the screen, so I know it's getting to the right bit of code.</p>
  <p>I tried sending the same link to the iPhone in an email and that does nothing either. (I tried that on the Android phone, and the email app wouldn’t even display the link as a hyperlink). Is there some setting on the iPhone, or in my app, to allow deep linking?</p>
  <p>As you may have guessed, I am not normally an iPhone user. I’m using an old iPhone 6 for testing, running iOS 12.4.8.</p>
  <p>I have sought help from the Zoom developer forum, who suggested that when using url schemes in iOS, there is an <code>AppDelegate</code> function that needs to be overridden:</p>
  <pre><code>func application(_ app: UIApplication, open url: URL, options: [UIApplication.OpenURLOptionsKey : Any] = [:]) -&gt; Bool
  </code></pre>
  <p>I'm guessing the above is not C#, and that the Essentials Launcher class deals with whatever is required in iOS.</p>
  <p>Am I missing something, or is this a bug? Any help gratefully appreciated.</p>