PyQt5表单界面间导航问题求助：登录与注册界面跳转失败

Let's break down what's going wrong with your current code and fix the navigation issue step by step.

Issues in Your First openwindow Function #

Your first approach has three critical mistakes:

• You're assigning the class itself (QtWidgets.QWidget/register.Ui_Register_Form) instead of creating an instance of them (missing parentheses ()).
• The setupUi method expects a window widget instance as its argument, not the UI class instance itself. This is why you're getting stuck at that line—you're passing the wrong object.

Issues in Your Second openwindow Function #

While this approach checks for existing window references, it's still incorrect because:

• You're directly instantiating the Ui_Register_Form class, but PyQt's auto-generated UI classes (from pyuic5) aren't standalone windows. They're designed to be attached to a parent widget (like QWidget or QMainWindow).

Correct Implementation #

Here are two robust ways to implement the navigation:

Method 1: Create a New Window with the Register UI #

This method creates a new top-level widget and attaches the register UI to it:

def open_register_window(self):
    # Create a new window widget
    self.register_window = QtWidgets.QWidget()
    # Instantiate the register UI class
    self.register_ui = register.Ui_Register_Form()
    # Attach the UI to the new window
    self.register_ui.setupUi(self.register_window)
    # Show the window
    self.register_window.show()

Method 2: Use a Single Window with Stacked Widgets (Better for App Flow) #

For a smoother user experience, consider using a QStackedWidget to switch between login and register forms within the same window instead of opening new windows. Here's a quick example:

1. In your main window, add a QStackedWidget as the central widget.
2. Add your login and register widgets to the stacked widget:

from PyQt5 import QtWidgets
import register  # Your register UI module
import login  # Your login UI module

class MainWindow(QtWidgets.QMainWindow):
    def __init__(self):
        super().__init__()
        self.stacked_widget = QtWidgets.QStackedWidget()
        self.setCentralWidget(self.stacked_widget)

        # Add login form
        self.login_widget = QtWidgets.QWidget()
        self.login_ui = login.Ui_Login_()
        self.login_ui.setupUi(self.login_widget)
        self.login_ui.Register_Button.clicked.connect(self.switch_to_register)
        self.stacked_widget.addWidget(self.login_widget)

        # Add register form
        self.register_widget = QtWidgets.QWidget()
        self.register_ui = register.Ui_Register_Form()
        self.register_ui.setupUi(self.register_widget)
        self.register_ui.Back_Button.clicked.connect(self.switch_to_login)
        self.stacked_widget.addWidget(self.register_widget)

        # Start with login form
        self.stacked_widget.setCurrentWidget(self.login_widget)

    def switch_to_register(self):
        self.stacked_widget.setCurrentWidget(self.register_widget)

    def switch_to_login(self):
        self.stacked_widget.setCurrentWidget(self.login_widget)

Binding the Button Correctly #

Make sure your button connection is set up properly in your login UI class:

# Inside your Ui_Login_ class's setupUi method or wherever you initialize the button
self.Register_Button.clicked.connect(self.open_register_window)  # Or switch_to_register if using stacked widgets

Key Notes #

• Always keep a reference to the window/widget (like self.register_window) to prevent it from being garbage collected and closing immediately.
• If you generated your UI files with pyuic5, remember that the Ui_* classes are just for setting up widgets—they don't represent the window itself. You need to create a separate widget to host them.

内容的提问来源于stack exchange，提问作者devnoob999