在MessageBox应用程序退出后，为什么?

Question

我有一个系统类和一个弹出消息框的动作。当我单击Ok to Messagebox时，应用程序退出....为什么?我不想辞职。如何解决这个问题?

import sys
from PyQt4 import QtGui, QtCore
class SystemTrayIcon(QtGui.QSystemTrayIcon):
    def __init__(self, icon, parent=None):
        QtGui.QSystemTrayIcon.__init__(self, icon, parent)
        menu = QtGui.QMenu(parent)
        exitAction = menu.addAction("Exit")
        helloAction = menu.addAction("Hello World")
        self.setContextMenu(menu)
        QtCore.QObject.connect(exitAction, QtCore.SIGNAL('triggered()'), self.exit)
        QtCore.QObject.connect(helloAction, QtCore.SIGNAL('triggered()'), self.hello)
    def exit(self):
        QtCore.QCoreApplication.exit()
    def hello(self):
       msg = QtGui.QMessageBox.information(self.parent(), "Hello", "Hello World")
def main():
    app = QtGui.QApplication(sys.argv)
    w = QtGui.QWidget()
    trayIcon = SystemTrayIcon(QtGui.QIcon("qtLogo.png"), w)
    trayIcon.show()
    sys.exit(app.exec_())
if __name__ == '__main__':
    main()

Answer 1

我明白了

需要设置app.setQuitOnLastWindowClosed(False)。所以:

app = QtGui.QApplication(sys.argv)
app.setQuitOnLastWindowClosed(False)