>If I remember correctly, the idea of the framework is to allow sorting on a second, third, ... column by doing a Ctrl-click. How will bindevent() figure out what parameters were passed to Header.MouseDown()?

The delegate method must have at least the number of parameters of the function or event it binds to

Stupid example -

If you take the parameters out of ScreenMouseDown, you will have an error when you click somewhere on the screen

=CreateObject('Resizer')


define class Resizer as relation

	function init()
		=DoDefault()
	
		=BindEvent(_screen, 'MouseDown', m.this, 'ScreenMouseDown', 1)
	
		=_screen.AddProperty('Resizer', m.this)
		
	endfunc
	
	
	function 	ScreenMouseDown(nButton, nShift, nXCoord, nYCoord)
	
		acti screen
		?'ScreenMouseDown', nButton, nShift, nXCoord, nYCoord
	endfunc
	
	function Destroy()
		
		try
			=UnBindEvents(m.this)
		
		catch
		
		endtry
		
		return DoDefault()
	endfunc
enddefine