PyQt4（简单信号槽）

import sys
from PyQt4 import QtCore, QtGui

class myWidget(QtGui.QWidget):
def __init__(self):
super(myWidget, self).__init__()
self.setWindowTitle("test")
self.resize(300, 200)
self.lab = QtGui.QLabel("label")
self.btn = QtGui.QPushButton("button")
hbox = QtGui.QHBoxLayout()
hbox.addWidget(self.lab)
hbox.addWidget(self.btn)
self.setLayout(hbox)
self.connect(self.btn, QtCore.SIGNAL('clicked()'), self, QtCore.SLOT('OnClick()'))

@QtCore.pyqtSlot()
def OnClick(self):
self.lab.setText("sdfasdf")

app = QtGui.QApplication(sys.argv)
wi = myWidget()
wi.show()
app.exec_()