title: Null check ObservableCollection before querying it
body: <p>Is this code good enough:</p>
  
  <pre><code>if (MyCollection.Where(p =&gt; p.SomeID == idstring).Any())
  {
     selectedval = MyCollection.Where(p =&gt; p.SomeID == idstring).FirstOrDefault().MyField;
  }
  </code></pre>
  
  <p>My doubt is about the fact that I make the same query twice: first for null check and then to actually get data.</p>
  
  <p>Maybe there is a better way to do this type of things?</p>