我有一个带有多个主窗口的 Qt 应用程序,我想在应用程序即将退出时收到一个信号,而所有窗口仍处于打开状态。
QApplication.aboutToQuit
信号对我不起作用,因为它只在所有窗口关闭后触发。
我看到的所有其他答案都建议实现主窗口的 closeEvent()
函数,但我有多个主窗口,我找不到任何方法来区分 CloseEvent
在仅关闭单个窗口的正常 closeEvent
和 QMD+Q
之后整个应用程序关闭或在任务中使用单击退出时的关闭事件之间bar 或出于任何原因退出。
如何仅在整个应用程序即将退出但在所有窗口关闭之前获得信号?
当我按下 Cmd+Q 或右键单击退出任务栏图标时会发生什么:
- (此时我想要一个信号)<-
- 所有窗口都有一个 closeEvent()
- aboutToQuit() 触发
- 应用退出
我想要的是在发生任何事情之前得到一个信号,并且所有的 window 仍然打开。
编辑:最小示例
from PyQt5.QtGui import QCloseEvent
from PyQt5.QtWidgets import QApplication, QWidget
class Win(QWidget):
def closeEvent(self, event: QCloseEvent):
# implementing a custom closeEvent doesn't help me
# this is called for every normal manual window close and when the application quits
# I only want to run something when the full application gets shut down, not just this window
# can't see any way to differentiate between the two
print("closeEvent", event.type(), event)
return super().closeEvent(event)
if __name__ == '__main__':
app = QApplication([])
app.aboutToQuit.connect(lambda :print("about to quit, this is too late, by now all windows are closed"))
#What I need
# app.beforeQuitSignal.connect(lambda :print("signal that it's gonna quit, before any of the windows are closed"))
#stuff I've tried that didn't work either
app.quit = lambda *args:print("quit, doesnt get called")
app.exit = lambda *args:print("exit, doesnt get called")
app.closeAllWindows = lambda *args:print("closeAllWindows, doesnt get called")
mainwins = []
for i in range(5):
win = Win()
win.setGeometry(100*i,100*i, 400,400), win.show(), win.raise_()
mainwins.append(win)
app.exec_()
最佳答案
如果你想在用户关闭窗口时触发一个信号,但不在最后一个窗口关闭后立即退出 QApplication
,你可以使用 QApplication.setQuitOnLastWindowClosed()
from PyQt5.QtCore import pyqtSignal
from PyQt5.QtGui import QCloseEvent
from PyQt5.QtWidgets import QApplication, QWidget
class Win(QWidget):
closing = pyqtSignal()
def closeEvent(self, event: QCloseEvent):
print("Window {} closed".format(self))
self.closing.emit()
return super().closeEvent(event)
class MyApp(QApplication):
def __init__(self, *args):
super(MyApp, self).__init__(*args)
self.setQuitOnLastWindowClosed(False)
self.lastWindowClosed.connect(self.onLastClosed)
self.mainwins = []
for i in range(5):
win = Win()
win.setGeometry(100 * i, 100 * i, 400, 400), win.show(), win.raise_()
self.mainwins.append(win)
def onLastClosed(self):
print("Last windows closed, exiting ...")
self.exit()
if __name__ == '__main__':
app = MyApp([])
app.exec_()
有了这个,当一个窗口关闭时,一个 closing()
信号被发出
关于qt - 在 QT 中关闭窗口之前获取应用程序退出信号,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/47761219/