/*垂直滚动条*/
QScrollBar:vertical{
    width:12px;
    border:1px solid rgba(0,0,0,50);
    margin:0px,0px,0px,0px;
    padding-top:15px;
    padding-bottom:15px;
}
QScrollBar::handle:vertical{
    width:16px;
    background:rgba(0,0,0,25%);
    min-height:20;
}
QScrollBar::handle:vertical:hover{
    background:rgba(0,0,0,50%);
    border:0px rgba(0,0,0,25%);
}
QScrollBar::sub-line:vertical{
    height:15px;
    border-image:url(:/Res/scroll_up.png);
    subcontrol-position:top;
}
QScrollBar::sub-line:vertical:hover{
    height:15px;
    background:rgba(0,0,0,25%);
    subcontrol-position:top;
}
QScrollBar::add-line:vertical{
    height:15px;
    border-image:url(:/Res/scroll_down.png);
    subcontrol-position:bottom;
}
QScrollBar::add-line:vertical:hover{
    height:15px;
    background:rgba(0,0,0,25%);
    subcontrol-position:bottom;
}
QScrollBar::add-page:vertical{
    background:rgb(255,255,255);
}
QScrollBar::sub-page:vertical{
    background:rgb(255,255,255);
}
QScrollBar::up-arrow:vertical{
    border-width:0px;
    max-height:16px;
    min-width:17px;
}
QScrollBar::down-arrow:vertical{
    border-style:outset;
    border-width:0px;
}

/*水平滚动条*/
QScrollBar:horizontal{
    height:12px;
    border:1px solid rgba(0,0,0,50);
    margin:0px,0px,0px,0px;
    padding-left:15px;
    padding-right:15px;
}
QScrollBar::handle:horizontal{
    height:16px;
    background:rgba(0,0,0,25%);
    min-width:20;
}
QScrollBar::handle:horizontal:hover{
    background:rgba(0,0,0,50%);
    border:0px rgba(0,0,0,25%);
}
QScrollBar::sub-line:horizontal{
    width:15px;
    border-image:url(:/Res/scroll_left.png);
    subcontrol-position:left;
}
QScrollBar::sub-line:horizontal:hover{
    width:15px;
    background:rgba(0,0,0,25%);
    subcontrol-position:left;
}
QScrollBar::add-line:horizontal{
    width:15px;
    border-image:url(:/Res/scroll_right.png);
    subcontrol-position:right;
}
QScrollBar::add-line:horizontal:hover{
    width:15px;
    background:rgba(0,0,0,25%);
    subcontrol-position:right;
}
QScrollBar::add-page:horizontal{
    background:rgb(255,255,255);
}
QScrollBar::sub-page:horizontal{
    background:rgb(255,255,255);
}

官方美化文档见自带文档的【Qt Style Sheets Examples】栏目中。