[Solved]how to use QDoubleValidator?

[dreamerindia]

Dear all,

i'm trying to 4 1/2 digit display of the multimeter. it should only display between -19999 to +19999.
I tried using QDoubleValidator as
@ QDoubleValidator *validate=new QDoubleValidator(this);
validate->setBottom(-19999);
validate->setTop(19999);
validate->setNotation(QDoubleValidator::StandardNotation);
ui->lineEdit->setValidator(validate);@

but it shows the range between -99999 to +99999

also i tried

@ QRegExp rx("[0-9]\d{0,4}");
ui->lineEdit->setValidator(new QRegExpValidator (rx, this));@

but it shows only between 0 to 99999.

kindly anybody can solve it?

[Edit: You only need an @ at the beginning and end of your code blocks, not every line. Cleaned up code -- mlong]

[mlong]

If I recall correctly, I believe that the validator will only check input typed at the keyboard. If you're trying to set the value through code, the validator won't stop you from doing so.

I wouldn't recommend using a QLineEdit as a display-only widget, which it sounds like you're doing. Consider a QLabel.

[dreamerindia]

Sorry for delay reply...

Can we control value in QLabel?

[Jake007]

It depends on how you mean value. You have setText() method in label class. You set number by doing so:
@myLabel->setText(QString::number(value));@

If you want value back to number, you only call:
@myLabel->text().toDouble();@

If you want to limit user input by value, you'll have to derive QValidator or QDoubleValidator, or you can use QDoubleSpinBox widget, which already has this built in.

Regards,
Jake