QComboBox样式表：字体、图标、项高

		QComboBox *cmBox = new QComboBox();
		cmBox->setStyleSheet("QComboBox{font-family:'微软雅黑';font-size:9; border:1px solid lightgray;}"
			"QComboBox QAbstractItemView::item {min-height: 20px;}"
			"QComboBox::drop-down{border-left-width: 1px;border-left-color: lightgray;border-left-style: solid; border-top-right-radius: 3px;border-bottom-right-radius: 3px;subcontrol-origin: padding;subcontrol-position: top right; width:20px;}"
			"QComboBox::down-arrow{image:url(:/FlightSimCaptain/Resources/down_arrow.png)}"
			"QComboBox::down-arrow:hover{image:url(:/FlightSimCaptain/Resources/down_arrow_press.png)}"
			"QComboBox::down-arrow:pressed{image:url(:/FlightSimCaptain/Resources/down_arrow_press.png)}");
		cmBox->addItem("04");
		cmBox->addItem("22");
		QStyledItemDelegate *delegate = new QStyledItemDelegate(this);
		cmBox->setItemDelegate(delegate);