Python PyQt4_uu如何从主窗口返回到登录窗口?
在以下示例中,如何在按下Python PyQt4_uu如何从主窗口返回到登录窗口?,python,python-3.x,qt,pyqt,pyqt4,Python,Python 3.x,Qt,Pyqt,Pyqt4,在以下示例中,如何在按下注销按钮后关闭主窗口并返回到登录窗口 import sys from PyQt4.QtCore import Qt from PyQt4.QtGui import QDialog, QPushButton, QVBoxLayout, QLineEdit, QMainWindow, QApplication, QMessageBox class LoginWindow(QDialog): def __init__(self): super().__init__
注销按钮后关闭主窗口
并返回到登录窗口
import sys
from PyQt4.QtCore import Qt
from PyQt4.QtGui import QDialog, QPushButton, QVBoxLayout, QLineEdit, QMainWindow, QApplication, QMessageBox
class LoginWindow(QDialog):
def __init__(self):
super().__init__()
self.build_UI()
def build_UI(self):
self.username = QLineEdit(self)
self.username.setPlaceholderText("Username: ")
self.password = QLineEdit(self)
self.password.setPlaceholderText("Password: ")
self.password.setEchoMode(QLineEdit.Normal)
self.logInButton = QPushButton("Log In")
self.logInButton.clicked.connect(self.handleLogin)
layout = QVBoxLayout()
layout.addWidget(self.username)
layout.addWidget(self.password)
layout.addWidget(self.logInButton)
self.setLayout(layout)
self.setWindowFlags(Qt.WindowSystemMenuHint)
self.show()
def handleLogin(self):
if self.username.text() == "abc" and self.password.text() == "123": # check credentials
self.accept()
else:
QMessageBox.warning(self, "Error", "Wrong username or password!")
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.logOutButton = QPushButton("Log Out", self)
self.logOutButton.pressed.connect(self.logOut)
self.show()
def logOut(self):
print("log Out")
def run():
app = QApplication(sys.argv)
login = LoginWindow()
if login.exec_() == QDialog.Accepted:
win = MainWindow()
sys.exit(app.exec_())
run()
在这种情况下,您希望首先启动主窗口,但在登录期间保持隐藏状态。对于注销事件,只需隐藏主窗口并再次显示登录。我在登录表单中添加了一个退出按钮,以便用户可以退出应用程序
请注意,我测试的是Qt5
class LoginWindow(QDialog):
def __init__(self):
super().__init__()
self.build_UI()
def build_UI(self):
self.username = QLineEdit(self)
self.username.setPlaceholderText("Username: ")
self.password = QLineEdit(self)
self.password.setPlaceholderText("Password: ")
self.password.setEchoMode(QLineEdit.Normal)
self.logInButton = QPushButton("Log In")
self.logInButton.clicked.connect(self.handleLogin)
self.ExitButton = QPushButton("Exit") # add exit button to exit app
self.ExitButton.clicked.connect(self.handleExit)
layout = QVBoxLayout()
layout.addWidget(self.username)
layout.addWidget(self.password)
layout.addWidget(self.logInButton)
layout.addWidget(self.ExitButton)
self.setLayout(layout)
self.setWindowFlags(Qt.WindowSystemMenuHint)
self.show()
def handleLogin(self):
self.accept()
def handleExit(self):
sys.exit() # close app
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.doLogin() # show login button before showing main window
self.logOutButton = QPushButton("Log Out", self)
self.logOutButton.pressed.connect(self.logOut)
self.show()
def logOut(self):
self.hide() # hide main window
self.doLogin() # show login
self.show()
def doLogin(self):
login = LoginWindow()
if login.exec_() != QDialog.Accepted:
self.close() # exit app
def run():
app = QApplication(sys.argv)
win = MainWindow()
sys.exit(app.exec_())
run()
如果要为每个登录重新创建主窗口,可以在run函数中使用循环。如果不想返回登录表单,则需要在主窗口中添加一个退出按钮
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.logOutButton = QPushButton("Log Out", self)
self.logOutButton.pressed.connect(self.logOut)
self.show()
def logOut(self):
self.close() # goes back to loop
def run():
app = QApplication(sys.argv)
while True: # need exit button to exit app
login = LoginWindow()
login.exec_() # will exit app if no login
win = MainWindow() # recreate main window
app.exec_()
run()
用于检查登录凭据:
def run():
app = QApplication(sys.argv)
while True: # need exit button to exit app
loginWindow = LoginWindow()
if loginWindow.exec_() == QDialog.Accepted: # user clicked login
usr = loginWindow.username.text()
pwd = loginWindow.password.text()
if usr == "abc" and pwd == "123": # check credentials
win = MainWindow() # recreate main window
app.exec_()
众多解决方案之一(最适合我的目的):
谢谢你的回答!难道没有其他不需要隐藏的方法吗?理想情况下,我更希望它能自动关闭和再次打开。在这种情况下,我不需要对代码做很多更改(比如根据用户重新初始化小部件的数据)。一方面,登录窗口没有接收信号,另一方面,即使我关闭登录窗口,它也会弹出主窗口。我并不是这个意思。我更新了代码,以便它按照我在代码中检查凭据的方式进行检查(为了缩短示例,我先跳过了它)。除此之外,您上传的第二和第三版本的代码完全相同。当我关闭登录窗口时,它仍然没有退出。你是说单击退出按钮打开主窗口?它调用sys.exit()
,这将终止应用程序。
import sys
from PyQt4.QtCore import Qt
from PyQt4.QtGui import QDialog, QPushButton, QVBoxLayout, QLineEdit, QMainWindow, QApplication, QMessageBox
class LoginWindow(QDialog):
def __init__(self):
super().__init__()
self.build_UI()
def build_UI(self):
self.username = QLineEdit(self)
self.username.setPlaceholderText("Username: ")
self.password = QLineEdit(self)
self.password.setPlaceholderText("Password: ")
self.password.setEchoMode(QLineEdit.Normal)
self.logInButton = QPushButton("Log In")
self.logInButton.clicked.connect(self.handleLogin)
layout = QVBoxLayout()
layout.addWidget(self.username)
layout.addWidget(self.password)
layout.addWidget(self.logInButton)
self.setLayout(layout)
self.setWindowFlags(Qt.WindowSystemMenuHint)
self.show()
def handleLogin(self):
if self.username.text() == "a" and self.password.text() == "a":
self.accept()
else:
QMessageBox.warning(self, "Error", "Wrong username or password!")
def closeEvent(self, event):
sys.exit()
class MainWindow(QMainWindow):
def __init__(self):
super().__init__()
self.return_to_login = False
self.logOutButton = QPushButton("Log Out", self)
self.logOutButton.pressed.connect(self.logOut)
self.show()
def logOut(self):
self.return_to_login = True
self.close()
def closeEvent(self, event):
if not self.return_to_login:
sys.exit()
def run():
app = QApplication(sys.argv)
while True:
loginWindow = LoginWindow()
if loginWindow.exec_() == QDialog.Accepted:
win = MainWindow()
app.exec_()
run()