QObject::connect: No such slot Widget::on_lineEdit_textEdited()

Rahul.k

i try to read the data from ardunio using the serial communication but when i used the connect function then its show the error no such slot widget. The on_lineEdit_textEdited function are also present and the slot are also include in widget.h but i cant understand where is problem how to solve that error .

QObject::connect(arduino,SIGNAL(readyRead()),this,SLOT(on_lineEdit_textEdited()));

void Widget::on_lineEdit_textEdited(const QString)
{
QByteArray serialData=arduino->readAll();
QString va_list=QString::fromStdString(serialData.toStdString());
qDebug()<<va_list;
}

J.Hilk

you're using the old signal slot syntax, therefore are you sure that inside your header the function
@Rahul.k said in QObject::connect: No such slot Widget::on_lineEdit_textEdited():

on_lineEdit_textEdited

is in the slots section and not just public or private?

mranger90

If you are using the old style connect, then you must put the argument:

QObject::connect(arduino,SIGNAL(readyRead(const QString )),this,SLOT(on_lineEdit_textEdited(const QString)));

aha_1980

@mranger90

... but you can omit the const and all spaces.

Anyway, on_lineEdit_textEdited will also be called automatically whenever lineEdit is edited, so please make sure to not shoot yourself in the foot.

Rahul.k

@J.Hilk In the on_lineEdit_textEdited() i define the private slots section

SGaist

Hi,

You wrote:
@Rahul.k said in QObject::connect: No such slot Widget::on_lineEdit_textEdited():

QObject::connect(arduino,SIGNAL(readyRead()),this,SLOT(on_lineEdit_textEdited()));

Yet your slot implementation signature is:
@Rahul.k said in QObject::connect: No such slot Widget::on_lineEdit_textEdited():

void Widget::on_lineEdit_textEdited(const QString)

So which one is the correct ?

In any case, that name is completely misleading with respect to what that function does and to what it's connected to. Thus you should rather give it a proper name.