Line Edit setText function Qt - c++

Question

I have a LineEdit which I want it to present a float value. I want the float value to have 2 digits precision so I used number function like this:
float tax = value * 0.23;
Qstring strTax = QString::number(tax, 'f', 2);
qDebug() << strTax;
ui->leTax->setText(strTax);
The thing is that while in console the value is printed with 2 digits precision, the widget prints all the decimal digits which might be 3 or more (depends on the value). Is there a way to fix it? I am using Qt 5.0.

Answer 1

So this is the accepted answer. I finally solved my problem. The onTextUpdate had to update two more LineEdits one containing the Tax and one containing The total amount. But the one containing the totalAmount also emitted the onTextChanged to update the net value and the Tax LineEdits, without rounding the values(I Was careless!!). So I corrected the totalAmount's onTextChanged. I also updated it to check if it has focus so to know if it is its turn to update the other LineEdits or not :). The point was that someone could edit the netValue line edit and that would update the tax and total amount or someone would enter the totalAmount and that automatically would update the net Amount and tax field. Everything working now. Thank you all for answering!!

Answer 2

I do not have a float-version for QString::number(), so maybe try cast-to-double
ui->leTax->setText(QString::number((double)tax, 'f', 2));
But since qDebug() is already showing the correct value, you probably change your strTax somewhere else in the code.

Answer 3

setValidator might be your solution. Click here and here
void QLineEdit::setValidator ( const QValidator * v )
Sets this line edit to only accept input that the validator, v, will accept. This allows you to place any arbitrary constraints on the text which may be entered.
Also, Set the number of decimal places with setDecimals().
So, it should looks like this :
// bottom (-999.0), top (999.0), decimals (2)
lineEdit->setValidator(new QDoubleValidator(-999.0, 999.0, 2, lineEdit));