如何在 PyQt5 中的消息框后保持對話框打開？

Question

我有一個名為“第一頁”的 QmainWindow，它有兩個按鈕“登錄”和“注冊”。這兩個按鈕都會打開 Qdialogs。 在我的登錄對話框中，我有兩行接受用戶輸入的編輯和兩個按鈕“取消”和“確定”。 單擊“確定”時，我想檢查一些驗證，例如如果行編輯為空，則在對話框頂部顯示一個 QmessageBox，然后在用戶單擊消息框上的“確定”后關閉消息框。

我的問題：當消息框打開時，對話框關閉。 PS：我一直在通過修改我剛剛發現的 QtDesigner 代碼來實現我的代碼，這是最糟糕的事情。 所以我又做了一遍。 我當時沒有這個問題。

我的代碼：

import sys
from PyQt5 import QtWidgets as qtw 
from PyQt5 import QtCore as qtc 
from PyQt5 import QtGui as qtg 
from first_page import Ui_first_page
from signin_page import Ui_signin_page
from signup_page import Ui_signup_page

class SignIn(qtw.QDialog):

    def __init__(self, *args, **kwargs):
        """SignIn constructor."""
        super().__init__(*args, **kwargs)
        self.ui = Ui_signin_page()
        self.ui.setupUi(self)

        # Connects the function that inputs data for sign in to the OK button.
        self.ui.signin_buttons.accepted.connect(self.sign_in_authenticate)

    def sign_in_authenticate(self):
        """Inputs the user's username and password for sign in process and checks validations"""
        input_username = self.ui.signin_username_lineEdit.text()
        input_password = self.ui.signin_password_lineEdit.text()

        # Check if both are filled
        if input_username == "":
            #MY PROBLEM IS HERE
            qtw.QMessageBox.critical(self,"Note", "Please input your username.")

        elif input_password == "":
            qtw.QMessageBox.critical(self, "Note", "Please input your password.")

        else: 
            # Checks validations and opens mainpage
            open_main_page(self, username, status)

    def open_main_page(self, username, status):
        """ Opens the main page after sign in"""
        pass

class FirstPage(qtw.QMainWindow):
    def __init__(self, *args, **kwargs):
        """FirstPage constructor."""
        super().__init__(*args, **kwargs)

        self.ui = Ui_first_page()
        self.ui.setupUi(self)

        # Connecting the buttons to open Sign in and Sign out pages
        self.ui.first_page_sign_in_button.clicked.connect(self.open_sign_in_page)
        self.ui.first_page_sign_up_button.clicked.connect(self.open_sign_up_page)

        self.show()

    def open_sign_in_page(self):
        self.sigin = SignIn()
        self.sigin.show()

    def open_sign_up_page(self):
        self.signup = SignUp()
        self.signup.show()


class SignUp(qtw.QDialog):
#Doesn't do anything yet.
    def __init__(self, *args, **kwargs):
        super().__init__(*args, **kwargs)
        self.ui = Ui_signup_page()
        self.ui.setupUi(self)

    
if __name__ == '__main__':
    app = qtw.QApplication(sys.argv)
    window = FirstPage()
    sys.exit(app.exec_())

我很新，所以如果我做錯了什么，請指出。 提前致謝。

我的問題的小例子：

主要代碼：

import sys
from PyQt5 import QtWidgets as qtw 
from PyQt5 import QtCore as qtc 
from PyQt5 import QtGui as qtg 
from mainwindow import Ui_MainWindow
from dialog import Ui_signin_Dialog

class SignIn(qtw.QDialog):

    def __init__(self, *args, **kwargs):
        """SignIn constructor."""
        super().__init__(*args, **kwargs)
        self.ui = Ui_signin_Dialog()
        self.ui.setupUi(self)

        # Connects the function that inputs data for sign in to the OK button.
        self.ui.signin_buttonBox.accepted.connect(self.sign_in_authenticate)

    def sign_in_authenticate(self):
        input_text = self.ui.input_lineEdit.text()

        if input_text == "":
            qtw.QMessageBox.critical(self,"Note", "Please input your data.")


class FirstPage(qtw.QMainWindow):
    def __init__(self, *args, **kwargs):
        """FirstPage constructor."""
        super().__init__(*args, **kwargs)

        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

        # Connecting the buttons to open Sign in and Sign out pages
        self.ui.signin_pushButton.clicked.connect(self.open_sign_in_page)

        self.show()

    def open_sign_in_page(self):
        self.sigin = SignIn()
        self.sigin.show()

if __name__ == '__main__':
    app = qtw.QApplication(sys.argv)
    window = FirstPage()
    sys.exit(app.exec_())

用戶界面主窗口：

class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(311, 293)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.signin_pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.signin_pushButton.setGeometry(QtCore.QRect(100, 110, 89, 25))
        self.signin_pushButton.setObjectName("signin_pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 311, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.signin_pushButton.setText(_translate("MainWindow", "Sign in "))

Ui_signin_Dialog

class Ui_signin_Dialog(object):
    def setupUi(self, signin_Dialog):
        signin_Dialog.setObjectName("signin_Dialog")
        signin_Dialog.resize(400, 300)
        self.signin_buttonBox = QtWidgets.QDialogButtonBox(signin_Dialog)
        self.signin_buttonBox.setGeometry(QtCore.QRect(290, 230, 80, 56))
        self.signin_buttonBox.setOrientation(QtCore.Qt.Vertical)
        self.signin_buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
        self.signin_buttonBox.setObjectName("signin_buttonBox")
        self.input_lineEdit = QtWidgets.QLineEdit(signin_Dialog)
        self.input_lineEdit.setGeometry(QtCore.QRect(140, 130, 113, 25))
        self.input_lineEdit.setObjectName("input_lineEdit")

        self.retranslateUi(signin_Dialog)
        self.signin_buttonBox.accepted.connect(signin_Dialog.accept)
        self.signin_buttonBox.rejected.connect(signin_Dialog.reject)
        QtCore.QMetaObject.connectSlotsByName(signin_Dialog)

    def retranslateUi(self, signin_Dialog):
        _translate = QtCore.QCoreApplication.translate
        signin_Dialog.setWindowTitle(_translate("signin_Dialog", "Dialog"))

我希望 Qmessagebox 像彈出消息一樣打開而不是關閉對話框。

Answer 1

嘗試一下：

import sys
from PyQt5 import QtWidgets as qtw 
from PyQt5 import QtCore as qtc 
from PyQt5 import QtGui as qtg 
from PyQt5 import QtCore, QtGui, QtWidgets                                 # +++


#from mainwindow import Ui_MainWindow
class Ui_MainWindow(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(311, 293)
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.signin_pushButton = QtWidgets.QPushButton(self.centralwidget)
        self.signin_pushButton.setGeometry(QtCore.QRect(100, 110, 89, 25))
        self.signin_pushButton.setObjectName("signin_pushButton")
        MainWindow.setCentralWidget(self.centralwidget)
        self.menubar = QtWidgets.QMenuBar(MainWindow)
        self.menubar.setGeometry(QtCore.QRect(0, 0, 311, 22))
        self.menubar.setObjectName("menubar")
        MainWindow.setMenuBar(self.menubar)
        self.statusbar = QtWidgets.QStatusBar(MainWindow)
        self.statusbar.setObjectName("statusbar")
        MainWindow.setStatusBar(self.statusbar)

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

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow"))
        self.signin_pushButton.setText(_translate("MainWindow", "Sign in "))
        
        
#from dialog import Ui_signin_Dialog
class Ui_signin_Dialog(object):
    def setupUi(self, signin_Dialog):
        signin_Dialog.setObjectName("signin_Dialog")
        signin_Dialog.resize(400, 300)
        self.signin_buttonBox = QtWidgets.QDialogButtonBox(signin_Dialog)
        self.signin_buttonBox.setGeometry(QtCore.QRect(290, 230, 80, 56))
        self.signin_buttonBox.setOrientation(QtCore.Qt.Vertical)
        self.signin_buttonBox.setStandardButtons(QtWidgets.QDialogButtonBox.Cancel|QtWidgets.QDialogButtonBox.Ok)
        self.signin_buttonBox.setObjectName("signin_buttonBox")
        self.input_lineEdit = QtWidgets.QLineEdit(signin_Dialog)
        self.input_lineEdit.setGeometry(QtCore.QRect(140, 130, 113, 25))
        self.input_lineEdit.setObjectName("input_lineEdit")

        self.retranslateUi(signin_Dialog)
#        self.signin_buttonBox.accepted.connect(signin_Dialog.accept)           # ---
        self.signin_buttonBox.rejected.connect(signin_Dialog.reject)
        QtCore.QMetaObject.connectSlotsByName(signin_Dialog)

    def retranslateUi(self, signin_Dialog):
        _translate = QtCore.QCoreApplication.translate
        signin_Dialog.setWindowTitle(_translate("signin_Dialog", "Dialog"))
        

class SignIn(qtw.QDialog):

    def __init__(self, *args, **kwargs):
        """SignIn constructor."""
        super().__init__(*args, **kwargs)
        self.ui = Ui_signin_Dialog()
        self.ui.setupUi(self)

        # Connects the function that inputs data for sign in to the OK button.
        self.ui.signin_buttonBox.accepted.connect(self.sign_in_authenticate)

    def sign_in_authenticate(self):
        input_text = self.ui.input_lineEdit.text()
        
        if input_text == "":
            qtw.QMessageBox.critical(self,"Note", "Please input your data.")
        else:                                                                   # +++
            self.accept()                                                       # +++


class FirstPage(qtw.QMainWindow):
    def __init__(self, *args, **kwargs):
        """FirstPage constructor."""
        super().__init__(*args, **kwargs)

        self.ui = Ui_MainWindow()
        self.ui.setupUi(self)

        # Connecting the buttons to open Sign in and Sign out pages
        self.ui.signin_pushButton.clicked.connect(self.open_sign_in_page)

        self.show()

    def open_sign_in_page(self):
        self.sigin = SignIn()
        self.sigin.show()

if __name__ == '__main__':
    app = qtw.QApplication(sys.argv)
    window = FirstPage()
    sys.exit(app.exec_())