Change date not working

[sousadaniel7]

Hi I'm trying to reschedule a QDate, but do not know why that is not working.

I have the following code:

qDebug() << ano2;
        qDebug() << mes2;
        qDebug() << dia2;
 
        bool b = ui->data_inicio->date().setDate(ano2, mes2, dia2);
        qDebug () << b;

qDebug() << ano2;
        qDebug() << mes2;
        qDebug() << dia2;

        bool b = ui->data_inicio->date().setDate(ano2, mes2, dia2);
        qDebug () << b;

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In qDebug appears fine. Until b returns true.

Why does not the date and amended?




regards,
Daniel Sousa

[amleto]

Not enough info. read sig.

Most likely date() returns a temporary and not the actual date object used in data_inicio. This is where reading the docs comes in handy.

[wysota]

date() returns a copy of the object. Calling setDate() on that will change the copy and not the original date object.

[sousadaniel7]

Not enough info. read sig.

Most likely date() returns a temporary and not the actual date object used in data_inicio. This is where reading the docs comes in handy.

But I've been reading and I do not understand the problem.

I do not know and explain how I change the date of a QDate through the code?

[amleto]

you've been reading? So you saw this http://qt-project.org/doc/qt-4.8/qdatetime.html#setDate ?

[sousadaniel7]

you've been reading? So you saw this http://qt-project.org/doc/qt-4.8/qdatetime.html#setDate ?

And that's what I did. The following code should work right?

bool b = ui->data_inicio->date().setDate(2012, 10, 5);

[d_stranz]

ui->data_inicio->date()

And what does this method return? Does it return QDate? Or QDate & ? If it returns QDate, then this is a temporary, a copy of the QDate stored in data_incio. Changing the copy has no effect at all on on the original QDate stored in data_incio.

Of course the setDate() function call will return true, because even if the QDate is a temporary, setting it to a new date will work just fine. It just has no effect, because at the end of that line of code, the copy is destroyed and whatever changes you made go with it.

[sousadaniel7]

And what does this method return? Does it return QDate? Or QDate & ? If it returns QDate, then this is a temporary, a copy of the QDate stored in data_incio. Changing the copy has no effect at all on on the original QDate stored in data_incio.

Of course the setDate() function call will return true, because even if the QDate is a temporary, setting it to a new date will work just fine. It just has no effect, because at the end of that line of code, the copy is destroyed and whatever changes you made go with it.

But then how can I do this?

[amleto]

And that's what I did. The following code should work right?

bool b = ui->data_inicio->date().setDate(2012, 10, 5);

no, that's not what you did, and no, it shouldn't work.

Look carefully!
http://qt-project.org/doc/qt-4.8/qdatetime.html#setDate
http://qt-project.org/doc/qt-4.8/qdate.html#setDate

and try again...

[wysota]

But then how can I do this?

Maybe you should call setDate() on the ui->data_inicio object?

[d_stranz]

Maybe you should call setDate() on the ui->data_inicio object?

Or maybe, since Daniel won't tell us what "data_inico" is, we can just keep guessing at answers until one of us guesses correctly.

[sousadaniel7]

Or maybe, since Daniel won't tell us what "data_inico" is, we can just keep guessing at answers until one of us guesses correctly.

ui->data_inicio is a QDateEdit

I've tried many ways and I can not change its value ...

[amleto]

try reading the thread

try reading the docs http://qt-project.org/doc/qt-4.8/qda...blic-functions

[sousadaniel7]

I managed to solve the problem.

Now I can not and the pm or am a QTimeEdit. I've had to do the builders and they do not allow for it ... How do I solve this?

[amleto]

http://qt-project.org/doc/qt-4.8/qda...layFormat-prop

[sousadaniel7]

http://qt-project.org/doc/qt-4.8/qda...layFormat-prop

I have the following code.

QStringList list_hora_inicio = fg.separarHora(query.value(8).toString());
        QString horaInicio = list_hora_inicio[0];
        QString minutosInicio = list_hora_inicio[1];
        QString amanha_tarde = list_hora_inicio[2];
        ui->hora_incio->setTime(QTime(horaInicio.toInt(&ok, 10), minutosInicio.toInt(&ok, 10)));

QStringList list_hora_inicio = fg.separarHora(query.value(8).toString());
        QString horaInicio = list_hora_inicio[0];
        QString minutosInicio = list_hora_inicio[1];
        QString amanha_tarde = list_hora_inicio[2];
        ui->hora_incio->setTime(QTime(horaInicio.toInt(&ok, 10), minutosInicio.toInt(&ok, 10)));

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Where do I put the AM or PM?

[amleto]

is there a brick wall I can borrow? ...

spoon feeding ...
qt-project.org/doc/qt-4.8/qdatetime.html#fromString

[ChrisW67]

Where do I put the AM or PM?

You don't. You read the documentation... it is obvious. I'll even highlight the bit that answers your question

QTime::QTime ( int h, int m, int s = 0, int ms = 0 )

Constructs a time with hour h, minute m, seconds s and milliseconds ms.
h must be in the range 0 to 23, m and s must be in the range 0 to 59, and ms must be in the range 0 to 999.

What is 3 PM on a 24-hour clock?

[d_stranz]

@amleto: is there a brick wall I can borrow? ...

Sorry, I'm using that wall right now. If you can answer the question in my post, I will let you have the wall until I need it again.