title: How to auto generate code for control property?
body: <p>I have a custom control,the control has a collection of property.</p>
  
  <p>I want to drag my control,auto add objects to the collection property of my control.</p>
  
  <p>Like <code>TabControl.TabPages</code> auto code.When drag <code>TabControl</code> to a form,auto create 2 <code>TabPage</code> add in <code>TabControl.TabPages</code>.</p>
  
  <p>How would I do that?</p>