[Gtk-sharp-list] treeview header size

[Andrei Ivanov]

Hello,
I've created a treeview and I'm trying to alter the size of its header.

The only way that I found about how to get a reference to the buttons 
that create the header is like this:

CellRendererText renderer = new CellRendererText();
TreeViewColumn column = new TreeViewColumn("Name", renderer, "text", 0);

column.Widget = new Gtk.Label("aa");
column.Widget.Show();
treeview1.AppendColumn(column);

//column.Widget -> Label
//column.Widget.Parent -> Alignment
//column.Widget.Parent.Parent -> HBox

Gtk.Button header = (Gtk.Button)column.Widget.Parent.Parent.Parent;

My problem is that I don't know how to alter the size of that button.

In glade, the common properties tab of a normal button include width and 
height, but the header button doesn't seem to have them.

Please help me...