How to link up calculations and QLineEdit

Question

I have a problem with managing to code the simple calculator. I have two QLineEdits, which I want to connect together, do simple calculations as addition, multiplication, and then show the result in the third QLineEdit, as shown in this picture.

What is exactly your doubt? Can you attach your code, please? — DYangu, May 29 '16 at 22:31
I want to do a calculator with different calculations but to the point. The user of a program writes for example how much he weights and how tall he is, as a result we get a BMI in the 3rd QLineEdit. And I don't really know now how and where put the necessary code. How to link them to read the variables, calculate them and show the result in the end. — , May 29 '16 at 22:37
No, I just wanted to ask what is the best way of achieving it. I can't figure out how to use the slots and signals in this case. — , May 29 '16 at 23:07

score 2 · Accepted Answer · answered May 30 '16 at 06:06

I think, the best components for such task are QDoubleSpinBox - http://doc.qt.io/qt-5/qdoublespinbox.html (for float and double values) or QSpinBox - http://doc.qt.io/qt-5/qspinbox.html (for integers values). Add button with name "Addition" and connect slot on button signal void QAbstractButton::clicked(bool checked = false) (http://doc.qt.io/qt-5/qabstractbutton.html#clicked). Your form will be like this:

form

The slot connected to "Addition" button clicked signal will be like this:

void MainWindow::slotPushButtonAdditionClicked(bool checked)
{
    Q_UNUSED(checked);
    ui->doubleSpinBoxResult->setValue(
                ui->doubleSpinBox1->value() +
                ui->doubleSpinBox2->value());
}

How to link up calculations and QLineEdit

1 Answers1