title: Add children to UserControl
body: <p>I created a user control and now I would like to be able to set it up so I can add children to each instance of it.</p>
  
  <p>This is how it's laid out:</p>
  
  <p><a href="https://i.stack.imgur.com/xudT8.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/xudT8.png" alt="enter image description here"></a></p>
  
  <p>The red boxes are panels that I'd like to be able to add children to. The idea is that I use this control in my winforms app, and from there drag and drop new controls into the red parent container.</p>
  
  <p>How do I do this?</p>