Qt- Hover QCombobox

Question

我试图自定义QCombobox。我创建了这个Combobox。

当我将这个组合框或事件封面悬停在整个组合框上时，我想删除蓝色背景颜色。
这是我的代码：

QComboBox {


        text-align: center;
        background: qlineargradient(x1:0, y1:0, x2:0, y2:1, stop:0 #797979, stop:0.48 #696969, stop:0.52 #5e5e5e, stop:1 #4f4f4f);
        padding: 2em 2em 2em 3em;
        min-width: 8em;
        color: #ffffff;
}
QComboBox::hover
{
    background: qlineargradient(x1:0, y1:0, x2:0, y2:1, stop:0 #797979, stop:0.48 #696969, stop:0.52 #5e5e5e, stop:1 #4f4f4f);
}
QComboBox::drop-down {
        subcontrol-origin: padding;
        subcontrol-position: top right;
        width: 20px;
        text-align: center;

}
QComboBox::down-arrow {
     image: url(:/images/arrows2.png);

}
QComboBox QAbstractItemView {
     outline: 0px;
}

QComboBox QAbstractItemView::item
{
    padding-left: 2em;
    text-align: center;
    height: 2em;
    background-color: lightgray;
}
QComboBox::down-arrow:on { /* shift the arrow when popup is open */

    image: url(:/images/arrows2.png);

}