Getting the attribute value from the DOM using Xamarin test FWK code

I have cross platform application which is already developed(not using Xamarin), for that I am writing a test case using Xamarin Test FWK to check whether a record is created or not.

Steps of the test cases.
1. Create a record using UI and that will navigate a newly created record page.
2. Fetch the gen-id from the DOM of the newly created record page using Xamarin test FWK code.
3. And hit the service using above created gen-id to test whether the record is created or not.

After creating the record, navigated new page which consists below DOM
<div gen-id="1234">....</div>

I want to fetch gen-id using Xamarin test FWK code from the above DOM so that i can hit the service using this gen-id to test whether the record is created or not with this gen-id.