如何从非 PyQt 类发出信号？

Question

我正在使用 Twisted 和 PyQt 在 python 中编写应用程序。我面临的问题是，当我扭曲代码中的一个函数被执行时，我必须在 GUI 中打印一行，我试图通过发出信号（非 PyQt 类）来实现这一点。这似乎不起作用，我怀疑扭曲的事件循环正在为 PyQt 搞砸事情。因为 closeEvent 信号没有被程序捕获。

这是代码片段：

from PyQt4 import QtGui, QtCore
import sys
from twisted.internet.protocol import Factory, Protocol
from twisted.protocols import amp
import qt4reactor

class register_procedure(amp.Command):
    arguments = [('MAC',amp.String()),
                        ('IP',amp.String()),
                        ('Computer_Name',amp.String()),
                        ('OS',amp.String())
                        ]
    response = [('req_status', amp.String()),
         ('ALIGN_FUNCTION', amp.String()),
                         ('ALIGN_Confirmation', amp.Integer()),
                         ('Callback_offset',amp.Integer())
                        ]

class Ui_MainWindow(QtGui.QMainWindow):

    def __init__(self,reactor, parent=None):
        super(Ui_MainWindow,self).__init__(parent)
        self.reactor=reactor
        self.pf = Factory()
        self.pf.protocol = Protocol
        self.reactor.listenTCP(3610, self.pf) # listen on port 1234

        def setupUi(self,MainWindow):
        MainWindow.setObjectName(_fromUtf8("MainWindow"))
        MainWindow.resize(903, 677)
        self.centralwidget = QtGui.QWidget(MainWindow)
        sizePolicy = QtGui.QSizePolicy(QtGui.QSizePolicy.Expanding, QtGui.QSizePolicy.Expanding)
        sizePolicy.setHorizontalStretch(0)
        sizePolicy.setVerticalStretch(0)
        sizePolicy.setHeightForWidth(self.centralwidget.sizePolicy().hasHeightForWidth())
        self.centralwidget.setSizePolicy(sizePolicy)

        self.create_item()


        self.retranslateUi(MainWindow)
        self.connect(self, QtCore.SIGNAL('triggered()'), self.closeEvent)
        QtCore.QObject.connect(self,QtCore.SIGNAL('registered()'),self.registered)
        QtCore.QMetaObject.connectSlotsByName(MainWindow)

    def retranslateUi(self, MainWindow):
        MainWindow.setWindowTitle(_translate("MainWindow", "MainWindow", None))
        self.pushButton_4.setText(_translate("MainWindow", "Delete System ", None))
        self.pushButton.setText(_translate("MainWindow", "Add System", None))
        self.label_2.setText(_translate("MainWindow", "SYSTEM STATUS", None))
        self.label.setText(_translate("MainWindow", "Monitoring Output", None))


    def registered(self):# this function is not being triggered
        print "check" 
        self.textbrowser.append()

    def closeEvent(self, event):#neither is this being triggered
        print "asdf"
        self.rector.stop()
        MainWindow.close()
        event.accept()


class Protocol(amp.AMP):
    @register_procedure.responder
    def register_procedure(self,MAC,IP,Computer_Name,OS):
        self.bridge_conn=bridge()
        cursor_device.execute("""select * FROM devices where MAC = ?;""",[(MAC)])
        exists_val=cursor_device.fetchone()
        cursor_device.fetchone()
        print "register"
        if not exists_val== "":
            cursor_device.execute("""update devices set IP= ? , Computer_name= ? , OS = ?  where MAC= ?;""",[IP,Computer_Name,OS,MAC])
            QtCore.QObject.emit( QtCore.SIGNAL('registered')) # <--emits signal
            return {'req_status': "done" ,'ALIGN_FUNCTION':'none','ALIGN_Confirmation':0,'Callback_offset':call_offset(1)}
        else:
            cursor_device.execute("""INSERT INTO devices(Mac,Ip,Computer_name,Os) values (?,?,?,?);""",[MAC,IP,Computer_Name,OS])
            QtCore.QObject.emit( QtCore.SIGNAL('registered'))#<--emits signal
            return {'req_status': "done" ,'ALIGN_FUNCTION':'main_loop()','ALIGN_Confirmation':0,'Callback_offset':0}



if  __name__ == "__main__":
    app = QtGui.QApplication(sys.argv)

    try:
        import qt4reactor
    except ImportError:
        from twisted.internet import qt4reactor
    qt4reactor.install()

    from twisted.internet import reactor
    MainWindow = QtGui.QMainWindow() # <-- Instantiate QMainWindow object.
    ui = Ui_MainWindow(reactor)
    ui.setupUi(MainWindow)
    MainWindow.show()
    reactor.run()

Answer 1

两个基本问题是：

1）某些东西必须知道信号的发送者和接收者

考虑 Qt 中更常见的情况，您可能有多个按钮，每个按钮都有一个“单击”信号。插槽需要知道单击了哪个按钮，因此捕获通用信号没有多大意义。

2) 信号必须源自 QObject。

话虽如此，我不确定规范的实现是什么。这是一种方法，使用您在之前的一篇文章中提到的 Bridge 的想法，以及 Protocol 中的特殊 Emitter 类。当调用 protocol.register() 时，运行此代码将简单地打印“Working it”。

from PyQt4 import QtGui, QtCore
import sys

class Ui_MainWindow(QtGui.QMainWindow):
    def __init__(self):
        super(Ui_MainWindow, self).__init__()

    def work(self):
        print "Working it"

class Protocol(object):
    class Emitter(QtCore.QObject):
        registered = QtCore.pyqtSignal()
        def __init__(self):
            super(Protocol.Emitter, self).__init__()

    def __init__(self):
        self.emitter = Protocol.Emitter()

    def register(self):
        self.emitter.registered.emit()

class Bridge(QtCore.QObject):
    def __init__(self, gui, protocol):
        super(Bridge, self).__init__()
        self.gui = gui
        self.protocol = protocol

    def bridge(self):
        self.protocol.emitter.registered.connect(self.gui.work)

app = QtGui.QApplication(sys.argv)
gui = Ui_MainWindow()
protocol = Protocol()
bridge = Bridge(gui, protocol)
bridge.bridge()
#protocol.register() #uncomment to see 'Working it' printed to the console