Vertical slider again

Payx

Hello,

My topic is mark as solved but i got a new error :

i have :

Hello guys,

i want to use a vertical slider to increase a variable

void MainWindow::on_verticalSlider_sliderMoved(int position)
{
    ui->verticalSlider->setRange(1,50);
z++;
}

but as i didn't expected, is that whenever the slider moove he will increment the variable z.

But i want that the slider decrease the variable z when he go down.
and increase when he go up !

thanks for your help

SGaist

Hi,

Do you mean you want z to have the same value as the slider ?

Payx

Yes exactly

SGaist

Then it's simply: z = position;

ambershark

void MainWindow::on_verticalSlider_sliderMoved(int position)
{
ui->verticalSlider->setRange(1,50);
z++;
}

Well you definitely don't need to call setRange more than once on a slider. So remove that line.

Then what you need is:

void MainWindow::on_verticalSlider_sliderMoved(int position)
{
   z = position;
}

Edit: @SGaist beat me to it. ;)

Payx

Thank you,

but i don't need a number for my "z" ?
How do we know the number of my variable ?

SGaist

What exactly do you want to do with z ?

What is your goals ?

That would help us understand what you are trying to achieve.

Payx

I have a slider who determine the value of "z"

i thought use a setrange for the slider (1 to 50)

Like if the vertical slider is at the bottom, the value of z will be 1
and if the slider is at the top the value of z will be 50

SGaist

Call setRange in your MainWindow constructor.

Payx

Call SetRange ? i don't undertsand

SGaist

That line: ui->verticalSlider->setRange(1,50); you should call it in the MainWindow constructor.

And since you are using a Designer based interface you can also set the min and max values in Designer and avoid the setRange call.

Payx

So the z=position;
i keep it ?

Sorry but even the "main constructor" it's the .cpp ? or .h ?

SGaist

Well... Yes if you use it somewhere else.

Payx

Yes i use the z somewhere else

thats why i needed a range 1 - 50

SGaist

Where exactly ? Depending on that, there's not even a need for z. You can get the value directly from the slider.

Payx

It depends where i use my "z" ?

How ?

Payx

thank's anyway,

3 h on it, i had time to ask help

ambershark

@Payx said in Vertical slider again:

It depends where i use my "z" ?

How ?

What do you use z for? Also side note, that's a horrible name for a variable locally much less one that is used at a class or global level.

What @SGaist is saying is you can always get the value of the slider from the slider itself without saving it to a variable. The function ui->verticalSlider->sliderPosition() will always contain the same value that your z would.

So with that in mind you can get rid of that whole overridden function and just call sliderPosition() when you need the value.