如何通过某些功能在PyQt5中切换屏幕？

Question

这是main.py：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'main.ui'
#
# Created by: PyQt5 UI code generator 5.13.0
#
# WARNING! All changes made in this file will be lost!

import sys

from PyQt5 import QtCore, QtGui, QtWidgets

import PyGravitySim.files.program as program


class Ui_main(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        sizePolicy = QtWidgets.QSizePolicy(QtWidgets.QSizePolicy.Fixed, QtWidgets.QSizePolicy.Preferred)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(MainWindow.sizePolicy().hasHeightForWidth())
        MainWindow.setSizePolicy(sizePolicy)
        MainWindow.setMinimumSize(QtCore.QSize(1920, 1080))
        MainWindow.setMaximumSize(QtCore.QSize(1920, 1080))
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        self.label = QtWidgets.QLabel(self.centralwidget)
        self.label.setGeometry(QtCore.QRect(0, 200, 1920, 250))
        font = QtGui.QFont()
        font.setFamily("Arial")
        font.setPointSize(72)
        font.setBold(True)
        font.setWeight(75)
        self.label.setFont(font)
        self.label.setAlignment(QtCore.Qt.AlignCenter)
        self.label.setObjectName("label")
        self.label_2 = QtWidgets.QLabel(self.centralwidget)
        self.label_2.setGeometry(QtCore.QRect(0, 520, 1920, 81))
        font = QtGui.QFont()
        font.setFamily("Arial")
        font.setPointSize(20)
        self.label_2.setFont(font)
        self.label_2.setAlignment(QtCore.Qt.AlignCenter)
        self.label_2.setObjectName("label_2")
        self.start_button = QtWidgets.QPushButton(self.centralwidget)
        self.start_button.setGeometry(QtCore.QRect(760, 730, 401, 131))
        font = QtGui.QFont()
        font.setFamily("Arial")
        font.setPointSize(30)
        self.start_button.setFont(font)
        self.start_button.setObjectName("start_button")
        self.start_button.clicked.connect(self.btn_clicked)
        MainWindow.setCentralWidget(self.centralwidget)

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

    def btn_clicked(self):
        program.startProgram()

    def retranslateUi(self, MainWindow):
        _translate = QtCore.QCoreApplication.translate
        MainWindow.setWindowTitle(_translate("MainWindow", "PyGravity Sim by Woojin K"))
        self.label.setText(_translate("MainWindow", "PyGravity Sim"))
        self.label_2.setText(_translate("MainWindow", "Made by Woojin K"))
        self.start_button.setText(_translate("MainWindow", "START"))


if __name__ == "__main__":
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_main()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

这是program.py：

# -*- coding: utf-8 -*-

# Form implementation generated from reading ui file 'program.ui'
#
# Created by: PyQt5 UI code generator 5.13.0
#
# WARNING! All changes made in this file will be lost!

import sys

from PyQt5 import QtCore, QtGui, QtWidgets


class Ui_program(object):
    def setupUi(self, MainWindow):
        MainWindow.setObjectName("MainWindow")
        MainWindow.resize(1920, 1080)
        MainWindow.setMinimumSize(QtCore.QSize(1920, 1080))
        MainWindow.setMaximumSize(QtCore.QSize(1920, 1080))
        self.centralwidget = QtWidgets.QWidget(MainWindow)
        self.centralwidget.setObjectName("centralwidget")
        MainWindow.setCentralWidget(self.centralwidget)
        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"))


def startProgram():
    app = QtWidgets.QApplication(sys.argv)
    MainWindow = QtWidgets.QMainWindow()
    ui = Ui_program()
    ui.setupUi(MainWindow)
    MainWindow.show()
    sys.exit(app.exec_())

这些文件只是空白示例。我通过uic命令制作了这些.py文件。

我刚刚在program.py上添加了startProgram()，并在main.py上将其导入。

如果按开始按钮，则退出代码为-1，程序崩溃。

我该如何解决这个问题？

Answer 1

Qt中仅存在一个QApplication实例，因此您永远不应创建并开始运行另一个实例。实际上，如果您尝试在IDE中或从shell /命令提示符下运行程序，则在退出之前，它可能会返回此代码：

QCoreApplication::exec: The event loop is already running

您实际上应该做的是从主脚本创建Ui：

from program import Ui_program

class Ui_main(object):
    # ...
    def btn_clicked(self):
        self.programWindow = QtWidgets.QMainWindow()
        ui = Ui_program()
        ui.setupUi(self.programWindow)
        self.programWindow.show()

就是说，这是not应该使用uic生成的文件的方式，因为您应该将它们保持原样并将其作为模块导入您的实际脚本中。阅读有关using Designer的官方PyQt文档，以了解如何实现ui文件及其生成的输出。