I want to write a code that increases the value in the line edit when the checkbox is clicked.

JonB

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

if i use originalLength function i got use of undeclared identifier 'originalLength' error

@J-Hilk said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

auto originalLength = ui->lineEdit->text().length();
ui->lineEdit->setText(QString::number(val).rightJustified(originalLength, '0'));

It's not a "function". So how did you get "undeclared identifier"?

wtimm

you are right it is not a function , thanks all of you for your help

wtimm

how can i see '0547' as default value when i run the project again

JonB

@wtimm
Well you need to save that value to some permanent storage to be able to retrieve it next time! Unless you are using a database in your application Qt's QSettings is the most convenient way.

wtimm

int v = settings.value(number(val),defaultValue).toInt();

I wrote such a code but it didn't work.
When I save the increased value, how can I make the increased value show as default when I open the project again?

Pl45m4

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

When I save the increased value, how can I make the increased value show as default when I open the project again?

Save the increased (always the current) value when you close your project?!

JonB

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

I wrote such a code but it didn't work.

Meaning what? Please don't just say "it didn't work" if you want people to understand enough to help. Your code shows reading back a value. How do we know what you saved where how? Did you look in the external INI file or Windows Registry to see what is there which has been saved?

When I save the increased value, how can I make the increased value show as default when I open the project again?

Read it back in somewhere at startup and set the widget's value from the previously saved.

wtimm

@Pl45m4 how can i save this , may i use QSettings or different class

JonB

@wtimm Already told you to save it via QSettings, there really isn't anything else to say....

wtimm

@JonB we have defined the variable val in the above answers (the value in the line edit)

Can we do it if we define val inside the setValue function or should we do it using another function?

void Widget::on_grabDataButton_clicked()
{
QSettings settings;
settings.setValue("val",1);
settings.value("val").toInt();
}

Pl45m4

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

void Widget::on_grabDataButton_clicked()
{
QSettings settings;
settings.setValue("val",1);
settings.value("val").toInt();
}

Dont know what this should do. Maybe you are using QSettings wrong.

To set value
settings.setValue("val", 42);

To read the value:
int val = settings.value("val").toInt();

And do whatever you like with val (set it to your line edit after you start your program)

wtimm

@JonB can you take a look at the code i wrote, where is my mistake ?

Pl45m4

@wtimm

The mistake is that it seems that you are not doing something with your value. It makes no sense to write and read the setting at the same place of your code (every time you click a button). Read it, where you need the value.

wtimm

@Pl45m4

void Widget::on_grabDataButton_clicked()
{
}

void Widget::on_mt_IncreaseValueButton_clicked()
{
auto originalLength = ui->mt_SerialNumberLineEdit->text().length();
auto val = ui->mt_SerialNumberLineEdit->text().toInt();
val += ui->mt_SpinBox->value();
ui->mt_SerialNumberLineEdit->setText(QString::number(val));
ui->mt_SerialNumberLineEdit->setText(QString::number(val).rightJustified(originalLength , '0'));
}
QSettings settings;
settings.setValue("val",42);
settings.value("val").toInt();

where should i use code in

Pl45m4

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

where should i use code in

Not in your buttonClicked handlers.

You save the current value one time, when you close your program and read it one time to write it back to your lineEdit, when you start your program.

e.g. your D'tor to save your value (obviously before you destroy your GUI) and maybe showEvent() to read your settings.

JonB

@JonB said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

When I save the increased value, how can I make the increased value show as default when I open the project again?

Read it back in somewhere at startup and set the widget's value from the previously saved.

SGaist

Hi,

@wtimm said in I want to write a code that increases the value in the line edit when the checkbox is clicked.:

settings.value("val").toInt();

What exactly do you think that line is doing ?
How can it change anything with regards to your widgets ?

wtimm

i don't quite understand how can i do this

SGaist

As others have already written:

read the settings into a variable
do any computation you might need (it might be none)
set the result on the widget that is supposed to contain it

wtimm

I can't code it