Python 当信号找不到其插槽时

单击按钮会导致进程崩溃。有什么不对劲吗

from PySide import QtCore, QtGui

class button(QtGui.QPushButton):
    def __init__(self, parent=None):
        super(button, self).__init__(parent) 
        self.clicked.connect(self.click)
        self.show()

    def click(self):
        self.emit(QtCore.SIGNAL('customSignal'), 'String Argument')

btn = button()

class label(QtGui.QLabel):
    def __init__(self, parent=None):
        super(label, self).__init__(parent) 
        self.connect(btn, QtCore.SIGNAL('customSignal'), self.Function) 
        self.show()   

    @QtCore.Slot(str)
    def Function(self, arg=None):
        print 'Function arg: %r'%arg

lbl = label()

---

不需要

@QtCore.Slot

装饰器：

from PyQt4 import QtCore, QtGui
import sys


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

    class button(QtGui.QPushButton):
        def __init__(self, parent=None):
            super(button, self).__init__(parent) 
            self.clicked.connect(self.click)
            self.show()

        def click(self):
            self.emit(QtCore.SIGNAL('customSignal'), 'String Argument')

    btn = button()

    class label(QtGui.QLabel):
        def __init__(self, parent=None):
            super(label, self).__init__(parent) 
            self.connect(btn, QtCore.SIGNAL('customSignal'), self.method) 
            self.show()   

        def method(self, arg=None):
            print 'method arg: %r'%arg

    lbl = label()


    sys.exit(app.exec_())

==================

from PySide import QtCore, QtGui

def function(arg=None):
    print 'function arg: %r'%arg

class button(QtGui.QPushButton):
    def __init__(self, parent=None):
        super(button, self).__init__(parent) 
        self.clicked.connect(self.click)
        self.show()

    def click(self):
        self.emit(QtCore.SIGNAL('customSignal'), 'String Argument')

btn = button()

class label(QtGui.QLabel):
    def __init__(self, parent=None):
        super(label, self).__init__(parent) 
        self.connect(btn, QtCore.SIGNAL('customSignal'), function) 
        self.show()   

lbl = label()

====

---

不需要

@QtCore.Slot

装饰器：

from PyQt4 import QtCore, QtGui
import sys


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

    class button(QtGui.QPushButton):
        def __init__(self, parent=None):
            super(button, self).__init__(parent) 
            self.clicked.connect(self.click)
            self.show()

        def click(self):
            self.emit(QtCore.SIGNAL('customSignal'), 'String Argument')

    btn = button()

    class label(QtGui.QLabel):
        def __init__(self, parent=None):
            super(label, self).__init__(parent) 
            self.connect(btn, QtCore.SIGNAL('customSignal'), self.method) 
            self.show()   

        def method(self, arg=None):
            print 'method arg: %r'%arg

    lbl = label()


    sys.exit(app.exec_())

==================

from PySide import QtCore, QtGui

def function(arg=None):
    print 'function arg: %r'%arg

class button(QtGui.QPushButton):
    def __init__(self, parent=None):
        super(button, self).__init__(parent) 
        self.clicked.connect(self.click)
        self.show()

    def click(self):
        self.emit(QtCore.SIGNAL('customSignal'), 'String Argument')

btn = button()

class label(QtGui.QLabel):
    def __init__(self, parent=None):
        super(label, self).__init__(parent) 
        self.connect(btn, QtCore.SIGNAL('customSignal'), function) 
        self.show()   

lbl = label()

====