title: C# WinForms showing a control as a dropdown
body: <p>Gretings </p>
  
  <p>I need to have a custom control for my application. Basically its an expression editing GUI. You have, say, expression:</p>
  
  <pre><code>If variable_x is greater than variable_y
  </code></pre>
  
  <p>And you can click on "greater than" and change it to other comparator (like, equal to or less than).</p>
  
  <p>The control thus must look like a label, but when you click it, it must show a dropdown (like combobox does) that has a listview inside (or maybe some other control) so that user can choose something. In a sense, i need a combobox without the box itself, replaced by something else (in this case, a label).</p>
  
  <p>I know how to make custom controls, i understand i must somehow DropDown on mouse click or enter keypress, and hook events so that when whatever i dropped has closed, the choice is made, and also somehow track if user clicked elsewhere so i can close this dropdowned control. But i dont know if this is easy to do (some built-in method exists) or i have to do it all myself? Dont want to redevelop the wheel....</p>
  
  <p>Please tell me if there are easy ways to do this.</p>
  
  <p>Thanks!</p>