有没有办法更改所有QMessageBox的OK按钮的样式表？

一个可能的解决方案是将 设置objectName()为每个按钮的选择器，为此您可以使用 的notify()方法QApplication：

from PySide2.QtCore import QEvent
from PySide2.QtWidgets import *
class Application(QApplication):
def notify(self, receiver, event):
if isinstance(receiver, QMessageBox) and event.type() == QEvent.Show:
for button in receiver.buttons():
sb = receiver.standardButton(button)
if not button.objectName():
button.setObjectName(sb.name.decode())
button.style().unpolish(button)
button.style().polish(button)
return super().notify(receiver, event)
def main():
app = Application()
app.setStyle("fusion")
app.setStyleSheet(
"""
QPushButton#Ok { background-color: green }
QPushButton#Cancel { background-color: red }
"""
)
QMessageBox.critical(
None, "Title", "text", buttOns=QMessageBox.Ok | QMessageBox.Cancel
)
msgBox = QMessageBox()
msgBox.setText("The document has been modified.")
msgBox.setInformativeText("Do you want to save your changes?")
msgBox.setStandardButtons(QMessageBox.Ok | QMessageBox.Cancel)
msgBox.exec_()
if __name__ == "__main__":
main()