gtk-sharp 2.10.0.0 Gtk# is thread aware, but not thread safe; See the Gtk# Thread Programming for details. The sizing method the column uses to determine its width. Please note that Autosize is inefficient for large views and can make columns appear choppy. System.Enum GLib.GType(WrapperType=typeof(Gtk.TreeViewColumnSizingGType)) Field Gtk.TreeViewColumnSizing Columns only get bigger in reaction to changes in the model. Field Gtk.TreeViewColumnSizing Columns resize to be the optimal size every time the model changes. Field Gtk.TreeViewColumnSizing Columns are a fixed numbers of pixels wide.