title: Preventing dropping an item onto self
body: <p>Ok, so I'm taking my first stab at Drag-Drop functionality here. I've handled mouse down and called DoDragDrop from my source control.</p>
  
  <p>What I'm trying to achieve is copying/ moving an account from one MDI child to another. In my context it makes no sense whatsoever to drop back onto the source control.</p>
  
  <p>I'm looking at the drag enter, where you provide information regarding the current effect.</p>
  
  <p>I'm wanting something that would look like the following:</p>
  
  <pre><code>If(eventData.Source != accountList)
  {
      eventData.Effect = DragDropEffects.Copy;
  }
  </code></pre>
  
  <p>However, I can't seem to find any way of determining the source control of the data. The only thing I could think of doing was having a custom class and pass that in the data with the source control embedded in that, or am I missing something obvious?</p>