PyQt5中如何通过Ui_Dialog的登录按钮切换到另一独立窗口类

你现有的两个Ui_xxx类是Qt Designer生成的界面模板，本身不属于窗口控件，只需将两个模板分别绑定到独立的QDialog子类，再在登录按钮的点击槽函数中触发第二个窗口的显示即可，完整实现逻辑如下：

from PyQt5 import QtCore, QtGui, QtWidgets

# 你原本的两个UI类代码直接放在这里即可，无需修改
class Ui_Dialog(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(409, 119)
        self.label_2 = QtWidgets.QLabel(Dialog)
        self.label_2.setGeometry(QtCore.QRect(20, 50, 61, 20))
        self.label_2.setAlignment(QtCore.Qt.AlignRight|QtCore.Qt.AlignTrailing|QtCore.Qt.AlignVCenter)
        self.label_2.setObjectName("label_2")
        self.lineEdit = QtWidgets.QLineEdit(Dialog)
        self.lineEdit.setGeometry(QtCore.QRect(90, 20, 221, 20))
        self.lineEdit.setObjectName("lineEdit")
        self.lineEdit_2 = QtWidgets.QLineEdit(Dialog)
        self.lineEdit_2.setGeometry(QtCore.QRect(90, 50, 221, 20))
        self.lineEdit_2.setObjectName("lineEdit_2")
        self.pushButton = QtWidgets.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(320, 20, 75, 81))
        self.pushButton.setObjectName("pushButton")
        self.label_3 = QtWidgets.QLabel(Dialog)
        self.label_3.setGeometry(QtCore.QRect(20, 20, 61, 20))
        self.label_3.setAlignment(QtCore.Qt.AlignRight|QtCore.Qt.AlignTrailing|QtCore.Qt.AlignVCenter)
        self.label_3.setObjectName("label_3")
        self.label_4 = QtWidgets.QLabel(Dialog)
        self.label_4.setGeometry(QtCore.QRect(20, 80, 61, 20))
        self.label_4.setAlignment(QtCore.Qt.AlignRight|QtCore.Qt.AlignTrailing|QtCore.Qt.AlignVCenter)
        self.label_4.setObjectName("label_4")
        self.lineEdit_3 = QtWidgets.QLineEdit(Dialog)
        self.lineEdit_3.setGeometry(QtCore.QRect(90, 80, 221, 20))
        self.lineEdit_3.setObjectName("lineEdit_3")

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
        self.label_2.setText(_translate("Dialog", "Password"))
        self.pushButton.setText(_translate("Dialog", "login"))
        self.label_3.setText(_translate("Dialog", "Email"))
        self.label_4.setText(_translate("Dialog", "distinct num"))


class Ui_Dialog2(object):
    def setupUi(self, Dialog):
        Dialog.setObjectName("Dialog")
        Dialog.resize(485, 429)
        self.textBrowser = QtWidgets.QTextBrowser(Dialog)
        self.textBrowser.setGeometry(QtCore.QRect(10, 30, 461, 281))
        self.textBrowser.setObjectName("textBrowser")
        self.label = QtWidgets.QLabel(Dialog)
        self.label.setGeometry(QtCore.QRect(10, 10, 121, 16))
        self.label.setObjectName("label")
        self.label_2 = QtWidgets.QLabel(Dialog)
        self.label_2.setGeometry(QtCore.QRect(20, 330, 211, 16))
        self.label_2.setObjectName("label_2")
        self.lineEdit = QtWidgets.QLineEdit(Dialog)
        self.lineEdit.setGeometry(QtCore.QRect(10, 350, 391, 20))
        self.lineEdit.setObjectName("lineEdit")
        self.pushButton = QtWidgets.QPushButton(Dialog)
        self.pushButton.setGeometry(QtCore.QRect(410, 350, 61, 23))
        self.pushButton.setObjectName("pushButton")
        self.pushButton_2 = QtWidgets.QPushButton(Dialog)
        self.pushButton_2.setGeometry(QtCore.QRect(10, 390, 461, 23))
        self.pushButton_2.setObjectName("pushButton_2")

        self.retranslateUi(Dialog)
        QtCore.QMetaObject.connectSlotsByName(Dialog)

    def retranslateUi(self, Dialog):
        _translate = QtCore.QCoreApplication.translate
        Dialog.setWindowTitle(_translate("Dialog", "Dialog"))
        self.label.setText(_translate("Dialog", "process"))
        self.label_2.setText(_translate("Dialog", "file"))
        self.pushButton.setText(_translate("Dialog", "select"))
        self.pushButton_2.setText(_translate("Dialog", "push"))


# 绑定UI到独立的QDialog子类
class LoginDialog(QtWidgets.QDialog, Ui_Dialog):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setupUi(self)
        # 绑定登录按钮点击事件
        self.pushButton.clicked.connect(self.handle_login)

    def handle_login(self):
        # 这里可以补充你原有的登录校验逻辑，比如验证邮箱、密码是否合法
        # 校验通过后实例化第二个窗口
        self.main_window = MainDialog()
        # 显示第二个窗口
        self.main_window.show()
        # 如果需要登录成功后关闭原登录窗口，取消下一行注释即可
        # self.close()


class MainDialog(QtWidgets.QDialog, Ui_Dialog2):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.setupUi(self)
        # 这里可以补充第二个窗口的控件逻辑，比如选择文件、推送操作的处理


# 主运行逻辑
if __name__ == "__main__":
    import sys
    app = QtWidgets.QApplication(sys.argv)
    login_window = LoginDialog()
    login_window.show()
    sys.exit(app.exec_())

关键说明 #

• 两个窗口是完全独立的QDialog实例，各自的尺寸、控件配置互不影响，符合你需要独立对话框的要求
• 第二个窗口的实例要存为登录窗口的实例属性（self.main_window），如果写成局部变量，函数执行完毕后变量会被垃圾回收，窗口会闪一下就消失
• 如果你需要第二个窗口是模态窗口（未关闭第二个窗口时无法操作其他窗口），把self.main_window.show()改为self.main_window.exec_()即可，这种情况不需要将实例存为属性也能正常运行

内容的提问来源于stack exchange，提问作者kwsong0314