title: xamarin picker control selectedindexchange event raised only when done picking item
body: <p>I am using an Xamarin.Forms.Picker control and handling the SelectedIndexChanged event. </p>
  
  <p>The user scrolls thru the items in the picker control then the user selects the "Done" button that is prebuilt into the picker control. Is there anyway to capture when the user presses "Done" instead of when the index changes. </p>
  
  <p>The index can change multiple times as the user scrolls thru the items and I don't want to handle unnecessary events as I only care about the last item selected.</p>
  
  <p>Thanks in advance</p>
  
  <pre><code>&lt;Picker x:Name="PickerMinStars" Title="Min number of 5 stars"  SelectedIndexChanged="Handle_PickerStarsSelectedIndexChanged"&gt;
          &lt;/Picker&gt;
  </code></pre>