问题[qt-designer]

开始学习QT Designer。我尝试构建一个试用界面，左侧是按钮（菜单），右侧是内容。按钮应该是固定大小并像我的一样堆叠在一起，但是我使用了框架和最大垂直策略来做到这一点。是否可以以相同的方式排列按钮，但没有框架？

测试.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <property name="styleSheet">
   <string notr="true">

    
QComboBox QListView {
   
    selection-background-color:white;
    
 }


}</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QComboBox" name="comboBox">
    <property name="geometry">
     <rect>
      <x>250</x>
      <y>110</y>
      <width>191</width>
      <height>41</height>
     </rect>
    </property>
    <property name="styleSheet">
     <string notr="true">QPushButton{
background-color: rgb(52, 58, 64);
color: rgb(255, 255, 255);
}
QPushButton::hover{
    /* background-color: rgb(90, 100, 111);*/
    background-color: rgb(79, 87, 97);
}

QComboBox{
background-color: rgb(52, 58, 64);
border:1px;
border-color:(170, 170, 255);
color: rgb(255, 255, 255);
}

QLabel{
background-color: rgb(108, 99, 118);
margin-top: 5px;
border-bottom: 2px solid  rgb(108, 99, 118);
border-top: 2px solid rgb(108, 99, 118);
}
QMainWindow{
background-color: rgb(244, 243, 248);
}
QComboBox::down-arrow
{   
    
    height: 15px;
    width: 20px;
    image: url(:/lol/arrow-up.png);
}
QWidget{
font: bold 15px;
font: Noto Sans;
color: rgb(255, 255, 255);
}
QCheckBox{
background-color: rgb(108, 99, 118);
margin-bottom: 5px;
}
QComboBox::drop-down {
   border:none;
}
QComboBox::hover{
background-color: rgb(90, 100, 111);
}
QComboBox QListView {
      background-color:rgb(52, 58, 64);
    selection-background-color:rgb(121, 121, 182);
    outline:none;
 }
/* этот код не работает*\
QComboBox QScrollBar::handle:vertical {
 background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0 rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155), stop:1 rgb(138, 147, 155));
 min-height: 0px
}
 QComboBox QScrollBar::add-line:vertical {
background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0 rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155),  stop:1 rgb(138, 147, 155));
height: 0px;
 subcontrol-position: bottom;
 subcontrol-origin: margin;
}
QComboBox QScrollBar::sub-line:vertical {
 background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0  rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155),  stop:1 rgb(138, 147, 155));
 height: 0 px;
subcontrol-position: top;
 subcontrol-origin: margin;
}
/*и так тоже не работает*\
QScrollBar::handle:vertical {
 background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0 rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155), stop:1 rgb(138, 147, 155));
 min-height: 0px
}
QScrollBar::add-line:vertical {
background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0 rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155),  stop:1 rgb(138, 147, 155));
height: 0px;
 subcontrol-position: bottom;
 subcontrol-origin: margin;
}
QScrollBar::sub-line:vertical {
 background: qlineargradient(x1:0, y1:0, x2:1, y2:0,
stop: 0  rgb(138, 147, 155), stop: 0.5 rgb(138, 147, 155),  stop:1 rgb(138, 147, 155));
 height: 0 px;
subcontrol-position: top;
 subcontrol-origin: margin;
}</string>
    </property>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

此代码在悬停时更改background对象combobox

QComboBox QListView {
selection-background-color: rgb(255, 255, 255); 
 }

测试.ui

<?xml version="1.0" encoding="UTF-8"?>
<ui version="4.0">
 <class>MainWindow</class>
 <widget class="QMainWindow" name="MainWindow">
  <property name="geometry">
   <rect>
    <x>0</x>
    <y>0</y>
    <width>800</width>
    <height>600</height>
   </rect>
  </property>
  <property name="windowTitle">
   <string>MainWindow</string>
  </property>
  <property name="styleSheet">
   <string notr="true">

    /* вот этот код работает */


QComboBox QListView {
      background-color:rgb(52, 58, 64);
    selection-background-color:white;
    
 }
/* а вот этот нет  */
QComboBox QListView::item:hover{
border:1px;
border-color: rgb(170, 85, 127);

}</string>
  </property>
  <widget class="QWidget" name="centralwidget">
   <widget class="QComboBox" name="comboBox">
    <property name="geometry">
     <rect>
      <x>250</x>
      <y>110</y>
      <width>69</width>
      <height>22</height>
     </rect>
    </property>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
    <item>
     <property name="text">
      <string>New Item</string>
     </property>
    </item>
   </widget>
  </widget>
  <widget class="QMenuBar" name="menubar">
   <property name="geometry">
    <rect>
     <x>0</x>
     <y>0</y>
     <width>800</width>
     <height>21</height>
    </rect>
   </property>
  </widget>
  <widget class="QStatusBar" name="statusbar"/>
 </widget>
 <resources/>
 <connections/>
</ui>

我需要更改border对象combobox

我StyleSheet通过Qt Designer添加。我找不到如何更改设置item comboBox。