title: Clearing ObservableCollection and Notifying UI
body: <p>I'm trying to clear my ObservableCollection <code>MyTruckCollection</code> of all of it's items. The issue I have is that it is not updating my UI after the collection has cleared of all items. </p>
  
  <p>I've tried clearing it with the following ways:</p>
  
  <p><code>MyTruckCollection.Clear();</code></p>
  
  <pre><code>foreach (var item in MyTruckCollection.ToList())
      MyTruckCollection.Remove(item);
  </code></pre>
  
  <p>I've tried this extension method:</p>
  
  <pre><code>    public static void RemoveAll&lt;T&gt;(this ObservableCollection&lt;T&gt; collection, Func&lt;T, bool&gt; condition)
      {
          for (int i = collection.Count - 1; i &gt;= 0; i--)
          {
              if (condition(collection[i]))
              {
                  collection.RemoveAt(i);
              }
          }
      }
  </code></pre>
  
  <p>And used it like this:</p>
  
  <p><code>MyTruckCollection.RemoveAll(x =&gt; x.TruckId != 0);</code></p>
  
  <p>They all remove all of the items, but my UI isn't being notified of the changes. Is there a way to notify my UI when I clear all of the data within the collection?</p>
  
  <p>NOTE: I also have PropertyChanged implemented on my MyTruckCollection.</p>