title: How to Access attached property set on parent control from child control instance
body: <p>I have a Canvas and inside the canvas i have a button. </p>
  
  <p>From the button instance i have set the <code>Canvas.Left</code> attached property. </p>
  
  <p>Now, from the button instance i have to access the value of the <code>Cavas.Left</code> attached property from code behind. </p>
  
  <p>How can i achieve this ?</p>
  
  <p>Ideally it should be done like : </p>
  
  <p>Canvas.SetLeft(buttonInstance,value) and accessed like 
  Canvas.GetLeft(buttonInstance) .. but i am not getting the value i have set. what whould be the cause of it. </p>
  
  <p>Thanks</p>