Value from combo box to LCD

[wysota]

I think you are missing "self" prefix when creating widgets. They don't land in the scope of your object.

[dayo30]

I think you are missing "self" prefix when creating widgets. They don't land in the scope of your object.

Thanks for your reply, but I do not understand it.

The plotting demo, from which I based mine, does not use self when creating widgets, and runs correctly.
The only thing that does not work, is my attempt to transfer a value from a combo box to an LCD.

I do not understand "land in the scope of your object". Could you explain, please?

Thanks,
Don

[wysota]

In "changeValue" you refer to some object "self.lcdVolts" but where is that object? I don't see you assigning anything to "self.lcdVolts" anywhere. "self.lcdVolts" and "lcdVolts" are two totally different objects.

[dayo30]

In "changeValue" you refer to some object "self.lcdVolts" but where is that object? I don't see you assigning anything to "self.lcdVolts" anywhere. "self.lcdVolts" and "lcdVolts" are two totally different objects.

Well, I added "self" to all places where it seemed appropriate. The program runs fine with, or without, "self", but the value is still not transferred to the LCD.

I'm still missing something, but can't figure out what.
Thanks for your patience,
Don

def createTopRightGroupBox(self):
        self.topRightGroupBox = QtGui.QGroupBox("Top Right")
 
        self.labelVolts = QtGui.QLabel("Volts/Div")
        self.labelVolts.setAlignment(QtCore.Qt.AlignHCenter)
 
        self.comboVolts = QtGui.QComboBox()
        volts = ['2.5', '5.0', '10.0', '20.0']
        self.comboVolts.addItems(volts)
 
        self.lcdVolts = QtGui.QLCDNumber()
 
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.labelVolts)
        layout.addWidget(self.comboVolts)
        layout.addWidget(self.lcdVolts)                 
        layout.addStretch(1)
        self.topRightGroupBox.setLayout(layout)
 
# process signal
        self.connect(self.comboVolts, QtCore.SIGNAL('valueChanged(double)'), self.changeValue)   
 
    def changeValue(self, event):
        volts = self.comboVolts.value()
        self.lcdVolts.display(volts)

def createTopRightGroupBox(self):
        self.topRightGroupBox = QtGui.QGroupBox("Top Right")

        self.labelVolts = QtGui.QLabel("Volts/Div")
        self.labelVolts.setAlignment(QtCore.Qt.AlignHCenter)
        
        self.comboVolts = QtGui.QComboBox()
        volts = ['2.5', '5.0', '10.0', '20.0']
        self.comboVolts.addItems(volts)
        
        self.lcdVolts = QtGui.QLCDNumber()
                       
        layout = QtGui.QVBoxLayout()
        layout.addWidget(self.labelVolts)
        layout.addWidget(self.comboVolts)
        layout.addWidget(self.lcdVolts)                 
        layout.addStretch(1)
        self.topRightGroupBox.setLayout(layout)
        
# process signal
        self.connect(self.comboVolts, QtCore.SIGNAL('valueChanged(double)'), self.changeValue)   
        
    def changeValue(self, event):
        volts = self.comboVolts.value()
        self.lcdVolts.display(volts)

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