Question

I am starting a Qt course this semester. Having looked at the official documentation as well as some on line examples I am confused by the parameter lists of the QInputDialog and QMessagebox classes.

Is there anywhere where one could find some decent info as to what to pass when creating the class / form?

Right now I have this by trial error

tempC = QInputDialog::getDouble(0, "Temperature Converter",
                                "Enter the temperature in Celsius to convert to Fahrenheit:", 1);

Looking at the official docs doesn’t help a lot either (at least not for me yet) as it says this:

double d = QInputDialog::getDouble(this, tr("QInputDialog::getDouble()"),
                                   tr("Amount:"), 37.56, -10000, 10000, 2, &ok);

as an example.

Any links will be much appreciated.

Answer 1

double d = QInputDialog::getDouble(this, tr("QInputDialog::getDouble()"),
                                   tr("Amount:"), 37.56, -10000, 10000, 2, &ok);

• A dialog will popup with parent the widget in which you are using this function. (this)
• The dialog’s title will be QInputDialog::getDouble() (tr is used in order to translate this string if you want using QtLinguist)
• Inside the dialog will be a double spibox and a label
• The label’s string will be Amount:
• The default value of the spinbox (what you see when the dialog popups) will be 37.56
• The minimum value will be -10000 (you will not be able to set a value less than this)
• The maximum value will be 10000 (you will not be able to set a value greater than this)
• Two decimal point will be displayed, eg 3.478 will be displayed as 3.48.
• If the user presses the Ok button then the ok argument will be set to true, otherwise it will be set to false

Check the documentation which includes an example for more details.