Connect slider and line edit??

[SGaist]

Hi,

You can use lambdas. Or you could also use QSpinBox rather than QLineEdit and thus you could connect the two directly.

[VRonin]

If you can use Qt5 and C++11

connect(ui->lightOff_R_LE, &QLineEdit::textChanged, [this](const QString& val)->void{ui->lightOff_R_S->setValue(val.toInt());});
	connect(ui->lightOff_R_S, &QSlider::valueChanged,[this](const int& val)->void{ui->lightOff_R_LE->setText(locale().toString(val));});

[QT-static-prgm]

@VRonin do you know how do bypass this error message?

connect(ui->ambCoef, &QSpinBox::valueChanged, [this](const double& value) {emit updateAmbCoef(value); });

it says it is not clear what instance of the overloaded function valueChanged should be used

[VRonin]

connect(ui->ambCoef, qOverload<double>(&QDoubleSpinBox::valueChanged), [this](const double& value) {emit updateAmbCoef(value); });

or if you are using qt<5.7

connect(ui->ambCoef, ststic_cast<void (&QDoubleSpinBox::*)(double)>(&QDoubleSpinBox::valueChanged), [this](const double& value) {emit updateAmbCoef(value); });

References:
https://wiki.qt.io/New_Signal_Slot_Syntax

http://doc.qt.io/qt-5/qtglobal.html#qOverload

[QT-static-prgm]

@VRonin both do not work

just see you had a typo.
static_cast<void (QDoubleSpinBox::*)(double)>
instead of
static_cast<void (&QDoubleSpinBox::*)(double)>

[VRonin]

what is ui->ambCoef ? it's unclear here if it's a QDoubleSpinBox or a QSpinBox

[QT-static-prgm]

doublespinbox. I found the problem. see my edit above

[SGaist]

Out of curiosity, why use a lambda in that case and not signal forwarding ?

[QT-static-prgm]

Because it does not work. I get qstring and need into and the other way around.

[SGaist]

But why use QLineEdit if you are only manipulating numbers ? That makes the code uselessly complicated.