title: Update View when property value changed inside setter
body: <p>I have checkbox in my view which has bound to the property in the viewmodel. When I check/uncheck the checkbox, there is one condition in setter of the property which updates the same property if the condition is true. But when the property gets updated corresponding view does not change.</p>
  
  <p>Here is the code:
  View:</p>
  
  <pre><code>&lt;CheckBox IsChecked="{Binding HoldingPen,Mode="Twoway" ,UpdateSourceTrigger=PropertyChanged}"/&gt;
  </code></pre>
  
  <p>ViewModel:</p>
  
  <pre><code>public bool HoldingPen
  {
    get{m_holdingPen;}
    set
    {
      m_hodingPen=value;
      onPropertyChanged("HoldingPen");
      OnHoldingPenCheckChanged();
    }
  
  public void OnHoldingPenCheckChanged()
  {
    if(HoldingPen &amp;&amp; some other condition)
    {
      HoldingPen=false;  //Here view should be updated simultaneously 
    }
  }
  </code></pre>