PyQt5 Python 中的程序设置是如何保存的？

Question

I have a desktop program with a choice of theme. How do I save a user's choice?

def Dark_Blue_Theme(self):
    style = open('themes/darkblue.css' , 'r')
    style = style.read()
    self.setStyleSheet(style)

def Dark_Gray_Theme(self):
    style = open('themes/darkgray.css' , 'r')
    style = style.read()
    self.setStyleSheet(style)

def Dark_Orange_Theme(self):
    style = open('themes/darkorange.css' , 'r')
    style = style.read()
    self.setStyleSheet(style)

def QDark_Theme(self):
    style = open('themes/qdark.css' , 'r')
    style = style.read()
    self.setStyleSheet(style)

Answer 1

The logic is to use QSettings to save the selected theme and then use it at the beginning of the program to load the theme:

import os

from PyQt5 import QtCore, QtGui, QtWidgets

CURRENT_DIR = os.path.dirname(os.path.realpath(__file__))
THEME_DIR = os.path.join(CURRENT_DIR, "themes")
DEFAULT_THEME = "qdark"


class MainWindow(QtWidgets.QMainWindow):
    def __init__(self, parent=None):
        super().__init__(parent)
        self._theme = ""

        self.restore_settings()
        self.load_theme()

        themes_menu = self.menuBar().addMenu(self.tr("Themes"))

        it = QtCore.QDirIterator(THEME_DIR, ["*.css"])
        group = QtWidgets.QActionGroup(self)
        group.triggered.connect(self.handle_theme_triggered)
        while it.hasNext():
            it.next()
            fi = it.fileInfo()
            action = QtWidgets.QAction(fi.baseName(), self)
            action.setCheckable(True)
            group.addAction(action)
            themes_menu.addAction(action)
            if fi.baseName() == self.theme:
                action.setChecked(True)

    def handle_theme_triggered(self, action):
        self._theme = action.text()
        self.load_theme()
        self.save_settings()

    @property
    def theme(self):
        return self._theme

    def save_settings(self):
        settings = QtCore.QSettings()
        settings.setValue("theme", self.theme)

    def restore_settings(self):
        settings = QtCore.QSettings()
        theme = settings.value("theme")
        if theme:
            self._theme = theme
        else:
            self._theme = DEFAULT_THEME
            self.save_settings()

    def load_theme(self):
        if self.theme:
            theme_file = os.path.join(THEME_DIR, self.theme + ".css")
            with open(theme_file) as f:
                style = f.read()
                self.setStyleSheet(style)

    def closeEvent(self, event):
        self.save_settings()
        super().closeEvent(event)


if __name__ == "__main__":
    import sys

    app = QtWidgets.QApplication(sys.argv)
    w = MainWindow()
    w.show()
    sys.exit(app.exec())

├── main.py
└── themes
    ├── darkblue.css
    ├── darkgray.css
    ├── darkorange.css
    └── qdark.css