如果我想使Gtk.TreeView可滚动，我将它嵌入到Gtk. ScrolledWindow中。嵌入TreeView会产生超出比例的光标（太大）。

TreeView中还有7行，低于所示的3行。我希望滚动条光标能缩放到1/3，让我可以舒适地滚动。
我可以用鼠标上的滚轮正常滚动，也可以用键盘上的箭头键滚动。
这是创建TextView的代码：

self.segment_store = Gtk.ListStore(str, str, str, str, str, str)
        self.segment_view = Gtk.TreeView(model = self.segment_store,
                    hexpand = True)
        
        self.segment_scroller = Gtk.ScrolledWindow()
        self.segment_scroller.add(self.segment_view)

ScrollledWindow本身被打包到Gtk. Grid中。
我怀疑滚动条中有一个属性指定了最小大小，并试图修改页面大小-再次没有运气。
这里有一个完整的最小例子。MainWindow中的if True可以更改为False，以启用/禁用ScrollWindow的使用。在create_segment_table中提到vadj的三行可以被注解掉，以禁用我的页面大小限制实验。

#!/usr/bin/env python3
# -*- coding: utf-8 -*-
#
#  test_embedded_treeview.py
#
#  Copyright 2023 John Coppens <john@jcoppens.com>
#
#  This program is free software; you can redistribute it and/or modify
#  it under the terms of the GNU General Public License as published by
#  the Free Software Foundation; either version 2 of the License, or
#  (at your option) any later version.
#
#  This program is distributed in the hope that it will be useful,
#  but WITHOUT ANY WARRANTY; without even the implied warranty of
#  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
#  GNU General Public License for more details.
#
#  You should have received a copy of the GNU General Public License
#  along with this program; if not, write to the Free Software
#  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
#  MA 02110-1301, USA.
#
#

import gi
gi.require_version('Gtk', '3.0')
from gi.repository import Gtk

class MainWindow(Gtk.Window):
    def __init__(self):
        super(MainWindow, self).__init__()
        self.connect("destroy", lambda x: Gtk.main_quit())
        self.set_default_size(400, 300)

        self.create_segment_table()
        for i in range(10):
            self.segment_store.append( ('0', )*6 )

        if True:
            grid = Gtk.Grid()
            grid.attach(self.segment_scroller, 1, 1, 1, 1)

            self.add(grid)
        else:
            self.add(self.segment_scroller)

        self.show_all()

    def run(self):
        Gtk.main()

    def create_segment_table(self):
        self.segment_store = Gtk.ListStore(str, str, str, str, str, str)
        self.segment_view = Gtk.TreeView(model = self.segment_store,
                    hexpand = True)
        #   La tabla puede crecer demasiado, asi que agregamos un 'scroller'
        self.segment_scroller = Gtk.ScrolledWindow()
        self.segment_scroller.add(self.segment_view)

        # Trying to change the page size of the scrollbar
        vadj = self.segment_scroller.get_vadjustment()
        vadj.set_page_size(20)
        self.segment_scroller.set_vadjustment(vadj)

        # Creamos las columnas para la tabla
        for colnr, header in enumerate( ('X0', 'Y0', 'Z0', 'X1', 'Y1', 'Z1') ):
            renderer = Gtk.CellRendererText(editable = True)
            # ~ renderer.connect('edited', self.on_cell_edited, colnr)
            col = Gtk.TreeViewColumn(header, renderer, text = colnr)
            col.set_expand(True)
            self.segment_view.append_column(col)

def main(args):
    mainwdw = MainWindow()
    mainwdw.run()

    return 0

if __name__ == '__main__':
    import sys
    sys.exit(main(sys.argv))

**编辑：**西尔维斯特下面的优秀答案是这个问题的好解决方案。因为这是对小部件缺陷的修正，而不是样式问题，所以我决定不使用外部的.CSS文件，因为这会使维护复杂化。所以我在代码中包含了CSS（注意load_from_data需要一个字节字符串）：

style_provider = Gtk.CssProvider()
        style_provider.load_from_data(b"slider {min-height: 10px; }"
                                      b"trough {min-height: 50px; }")

        Gtk.StyleContext.add_provider_for_screen(
            Gdk.Screen.get_default(),
            style_provider,
            Gtk.STYLE_PROVIDER_PRIORITY_USER
        )