设定QComboBox 的背景颜色，边框设定，以及下拉框的背景颜色以及边框设定，
selection-background-color 不生效可忽略 xxx_source = QComboBox(self.xxx_frame)
xxx_source.setStyleSheet("QComboBox {background-color: transparent; color: transparent; border-radius: 10px;\
border-color: lightgray; border-style: solid; border-width:0px; padding-left:5px;} \
QComboBox QAbstractItemView {\
border: none;\
background: #181818;\
selection-background-color: blue;\
}")
标签：设定,python,QComboBox,pyqt6,color,background,border,下拉框 From： https://www.cnblogs.com/uoky/p/17968087