How to connect a slider to a function in PyQt4?

Question

Im trying to translate the value of a slider into a function and display the value of this function as a lineEdit widget. Here is my code:

class MyForma1(object): def AddWidgets1(self, Form): Form.setObjectName(_fromUtf8("Form")) Form.resize(579, 542) self.horizontalSlider = QtGui.QSlider(Form) self.horizontalSlider.setGeometry(QtCore.QRect(120, 380, 321, 31)) self.horizontalSlider.setOrientation(QtCore.Qt.Horizontal) self.horizontalSlider.setInvertedAppearance(False) self.horizontalSlider.setInvertedControls(False) self.horizontalSlider.setObjectName(_fromUtf8("horizontalSlider")) self.lineEdit = QtGui.QLineEdit(Form) self.lineEdit.setGeometry(QtCore.QRect(112, 280, 331, 20)) self.lineEdit.setObjectName(_fromUtf8("lineEdit")) self.retranslateUi(Form) QtCore.QObject.connect(self.horizontalSlider, QtCore.SIGNAL('valueChanged(int)'), Form.changeText) def retranslateUi(self, Form): Form.setWindowTitle(_translate("Form", "Form", None)) class MyForma2(QtGui.QDialog, MyForma1): def __init__(self, z11=0): QtGui.QDialog.__init__(self) self.AddWidgets1(self) self.z = z11 def myfunc1(self): self.z = self.horizontalSlider.value def changeText(self): self.myfunc1() self.lineEdit.setText(str(self.z)) if __name__ == "__main__": import sys app = QtGui.QApplication(sys.argv) Forma = MyForma2() Forma.show() sys.exit(app.exec_()) 

I want to get the value of the slider and assign it to self.z , in which case I would like to know what I should write instead: self.z = self.horizontalSlider.value

Answer 1

This should be self.horizontalSlider.value() , since value is callable. However, the QHorizontalSlider.valueChanged signal also emits a slider value, so you can change your changeText method as follows:

 def changeText(self, value): self.z = value self.lineEdit.setText(str(self.z)) 

We also consider the use of new style signal slot mechanisms: http://pyqt.sourceforge.net/Docs/PyQt4/new_style_signals_slots.html