QPushButton修改背景失效

QPushButton修改背景失效 修改悬停背景及按下背景不起作用 Google translate: "Modifying the background does not work. Modifying the hover background and pressing the background does not work."

setStyleSheet（"QPushButton:pressed { background-color:  red; color: black;}"
                         "QPushButton:hover { background-color: blue; color: black;}"）

不管修改什么背景颜色都不起作用，字体可以正常修改 Google translate: No matter what background color you modify, it does not work. The font can be modified normally.