title: Get the current view controller from the app delegate
body: <p>i am new to ios. I need to know the current view controller from app delegate.. i have no idea about this and i don't knowto implement this.  i am using this code toimplemnt this but it return null values.
  I followed this link-
  <a href="https://stackoverflow.com/questions/20485585/get-current-view-controller-from-the-app-delegate-modal-is-possible">Get current view controller from the app delegate (modal is possible)</a>
  need help.</p>