在实现这两个功能的时候，需要用到QSettings这个知识点。QSettings用起来还是很方便，很简单的，不细说了，直接看代码吧。

保存登录信息

    # 保存登录信息
    def save_login_info(self):
        settings = QSettings("config.ini", QSettings.IniFormat)
        settings.setValue("account",self.lineEdit_account.text())
        settings.setValue("password", self.lineEdit_password.text())
        settings.setValue("remeberpassword", self.checkBox_remeberpassword.isChecked())
        settings.setValue("autologin", self.checkBox_autologin.isChecked())

初始化登录信息

    # 初始化登录信息
    def init_login_info(self):
        settings = QSettings("config.ini", QSettings.IniFormat)
        the_account =settings.value("account")
        the_password = settings.value("password")
        the_remeberpassword = settings.value("remeberpassword")
        the_autologin = settings.value("autologin")        ########
        self.lineEdit_account.setText(the_account)        if the_remeberpassword=="true" or  the_remeberpassword==True:
            self.checkBox_remeberpassword.setChecked(True)
            self.lineEdit_password.setText(the_password)        if the_autologin=="true" or  the_autologin==True:
            self.checkBox_autologin.setChecked(True)        if the_autologin == "true":   #防止注销时，自动登录
            threading.Timer(1, self.on_pushButton_enter_clicked).start()            #self.on_pushButton_enter_clicked()

完整代码

【如下代码，完全复制，直接运行，即可使用】

import sysfrom PyQt5.QtWidgets import *from PyQt5.QtCore import *from PyQt5.QtGui import *import threading#######################################################创建主窗口################################################class MainWindow(QMainWindow):
    windowList = []    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setWindowTitle('主界面')
        self.showMaximized()        # 创建菜单栏
        self.createMenus()    def createMenus(self):
        # 创建动作 注销
        self.printAction1 = QAction(self.tr("注销"), self)
        self.printAction1.triggered.connect(self.on_printAction1_triggered)        # 创建动作 退出
        self.printAction2 = QAction(self.tr("退出"), self)
        self.printAction2.triggered.connect(self.on_printAction2_triggered)        # 创建菜单，添加动作
        self.printMenu = self.menuBar().addMenu(self.tr("注销和退出"))
        self.printMenu.addAction(self.printAction1)
        self.printMenu.addAction(self.printAction2)    # 动作一：注销
    def on_printAction1_triggered(self):
        self.close()
        dialog = logindialog()        if  dialog.exec_()==QDialog.Accepted:
            the_window = MainWindow()
            self.windowList.append(the_window)    #这句一定要写，不然无法重新登录
            the_window.show()    # 动作二：退出
    def on_printAction2_triggered(self):
        self.close()    # 关闭界面触发事件
    def closeEvent(self, event):
        print(999999999)        pass#######################################################对话框################################################class logindialog(QDialog):
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.setWindowTitle('登录界面')
        self.resize(200, 200)
        self.setFixedSize(self.width(), self.height())
        self.setWindowFlags(Qt.WindowCloseButtonHint)        ###### 设置界面控件
        self.frame = QFrame(self)
        self.verticalLayout = QVBoxLayout(self.frame)

        self.lineEdit_account = QLineEdit()
        self.lineEdit_account.setPlaceholderText("请输入账号")
        self.verticalLayout.addWidget(self.lineEdit_account)

        self.lineEdit_password = QLineEdit()
        self.lineEdit_password.setPlaceholderText("请输入密码")
        self.verticalLayout.addWidget(self.lineEdit_password)

        self.checkBox_remeberpassword = QCheckBox()
        self.checkBox_remeberpassword.setText("记住密码")
        self.verticalLayout.addWidget(self.checkBox_remeberpassword)

        self.checkBox_autologin = QCheckBox()
        self.checkBox_autologin.setText("自动登录")
        self.verticalLayout.addWidget(self.checkBox_autologin)


        self.pushButton_enter = QPushButton()
        self.pushButton_enter.setText("确定")
        self.verticalLayout.addWidget(self.pushButton_enter)

        self.pushButton_quit = QPushButton()
        self.pushButton_quit.setText("取消")
        self.verticalLayout.addWidget(self.pushButton_quit)        ###### 绑定按钮事件
        self.pushButton_enter.clicked.connect(self.on_pushButton_enter_clicked)
        self.pushButton_quit.clicked.connect(QCoreApplication.instance().quit)        ####初始化登录信息
        self.init_login_info()    def on_pushButton_enter_clicked(self):
        # 账号判断
        if self.lineEdit_account.text() == "":            return

        # 密码判断
        if self.lineEdit_password.text() == "":            return


        ####### 保存登录信息
        self.save_login_info()        # 通过验证，关闭对话框并返回1
        self.accept()    # 保存登录信息
    def save_login_info(self):
        settings = QSettings("config.ini", QSettings.IniFormat)
        settings.setValue("account",self.lineEdit_account.text())
        settings.setValue("password", self.lineEdit_password.text())
        settings.setValue("remeberpassword", self.checkBox_remeberpassword.isChecked())
        settings.setValue("autologin", self.checkBox_autologin.isChecked())    # 初始化登录信息
    def init_login_info(self):
        settings = QSettings("config.ini", QSettings.IniFormat)
        the_account =settings.value("account")
        the_password = settings.value("password")
        the_remeberpassword = settings.value("remeberpassword")
        the_autologin = settings.value("autologin")        ########
        self.lineEdit_account.setText(the_account)        if the_remeberpassword=="true" or  the_remeberpassword==True:
            self.checkBox_remeberpassword.setChecked(True)
            self.lineEdit_password.setText(the_password)        if the_autologin=="true" or  the_autologin==True:
            self.checkBox_autologin.setChecked(True)        if the_autologin == "true":   #防止注销时，自动登录
            threading.Timer(1, self.on_pushButton_enter_clicked).start()            #self.on_pushButton_enter_clicked()#######################################################程序入门################################################if __name__ == "__main__":
    app = QApplication(sys.argv)
    dialog = logindialog()    if  dialog.exec_()==QDialog.Accepted:
        the_window = MainWindow()
        the_window.show()
        sys.exit(app.exec_())

作者：一心狮
链接：https://www.jianshu.com/p/e07201a5521d