title: Combobox with checkbox in winforms
body: <p>I am trying to look for a simple way to design a winform with a combobox that has checkbox values in it to select multiple values.
  But there are no free samples I could find. </p>
  
  <p>If anybody has a good link for a sample which does not require a license. 
  Please let me know.</p>
  
  <p>I am not looking for controls like telerik and infragistics.</p>