问如何将值从一个窗口传递到另一个PyQT

EN

import sys

from PyQt5 import QtCore as qtc
from PyQt5 import QtWidgets as qtw


class SubWindow(qtw.QWidget):
    submitClicked = qtc.pyqtSignal(str)  # <-- This is the sub window's signal
    
    def __init__(self, parent=None):
        super().__init__(parent)
        layout = qtw.QVBoxLayout()
        self.setLayout(layout)
        self.line_edit = qtw.QLineEdit(placeholderText="Enter URL here:")
        self.btn = qtw.QPushButton("Submit")
        layout.addWidget(self.line_edit)
        layout.addWidget(self.btn)
        self.btn.clicked.connect(self.confirm)

    def confirm(self):  # <-- Here, the signal is emitted *along with the data we want*
        self.submitClicked.emit(self.line_edit.text())
        self.close()


class MainWindow(qtw.QWidget):
    def __init__(self, parent=None):
        super().__init__(parent)
        self.sub_window = None  # placeholder attribute for the sub window
        layout = qtw.QVBoxLayout()
        self.setLayout(layout)
        self.label = qtw.QLabel("Current URL: None")
        self.btn = qtw.QPushButton("Get new URL...")
        layout.addWidget(self.label)
        layout.addWidget(self.btn)
        self.btn.clicked.connect(self.show_sub_window)

    def show_sub_window(self):  # <-- Here, we create *and connect* the sub window's signal to the main window's slot
        self.sub_window = SubWindow()
        self.sub_window.submitClicked.connect(self.on_sub_window_confirm)
        self.sub_window.show()
    
    def on_sub_window_confirm(self, url):  # <-- This is the main window's slot
        self.label.setText(f"Current URL: {url}")


if __name__ == "__main__":
    app = qtw.QApplication(sys.argv)
    gui = MainWindow()
    gui.show()
    sys.exit(app.exec_())