Add to QByteArray from TextBox

[joe1652]

Hello, I have a lineEdit text box on my GUI Form which I plan to enter in a number such as float. I want to add the contents of the lineEdit box to a QByteArray.

Something like:
QByteArray data = QByteArray::number(ui->lineEdit_0->text());

But when I try I get:

mainwindow.cpp:39: error: no matching function for call to 'QByteArray::number(QString)'
QByteArray data = QByteArray::number(ui->lineEdit_0->text());
^

I intend to use the QByteArray to transmit UDP data:
udp->writeDatagram(data.data(),size,QHostAddress(this->ip),srcPort);

Can anyone help out a newbie please.

Thank you
Joe

[JKSH]

Hi, and welcome!

@joe1652 said in Add to QByteArray from TextBox:

mainwindow.cpp:39: error: no matching function for call to 'QByteArray::number(QString)'
     QByteArray data = QByteArray::number(ui->lineEdit_0->text());
                                                                ^

• QByteArray::number() converts a number (int, float, double, etc.) to an 8-bit string. This is not what you want.
• QLineEdit::text() returns a QString. When you call this, your number is already stored a (16-bit) string.
• QString::toUtf8() converts a QString to a QByteArray (using UTF-8 encoding)

[joe306]

Hello, thank you for responding to my message. I'm a little slow here.

QByteArray data = QByteArray:: what goes here (ui->lineEdit_0->text() );

Sorry to ask you again for help.

[JonB]

@joe306

QByteArray data = ui->lineEdit_0->text().toUtf8();

[JKSH]

@joe306 It might make it clearer to break the code up into smaller segments. @JonB's code is equivalent to:

QString str = ui->lineEdit_0->text();
QByteArray data = str.toUtf8();

Does this make sense?