TestRange.cs error CS0104: `Range' is an ambiguous reference between `System.Range' and Gtk.Range

编译错误：

./TestCombo.cs(17,14): warning CS0612: `Gtk.Combo' is obsolete
./TestRange.cs(35,6): error CS0104: `Range' is an ambiguous reference between `System.Range' and `Gtk.Range'

意思就是，编译时不知道用哪个。那么应该用哪个？这个貌似是测试用的，所以吾用了Gtk，编译通过即可。