How increase and decrease progress bar with checkbox in Qt?

Question

I want when i check each box, progress bar increase %20 and when i unchecked box, progress bar decreased %20.

Answer 1

Connect to QCheckBox::stateChanged(int state) signal, and change the progressbar value according to signal state.

Edit

Following the comments, I will update the answer further more. Like I said you need to connect to QCheckBox::stateChanged(int state) signal from each QCheckBox you have.

To connect to signal you use:

connect(ui->checkBox, &QCheckBox::stateChanged, this, &MainWindow::Update_ProgressBar);
connect(ui->checkBox_2, &QCheckBox::stateChanged, this, &MainWindow::Update_ProgressBar);
...

And the slot will be:

void MainWindow::Update_ProgressBar(int value)
{
    int currentValue = ui->progressBar->value();
    if(value == 0)ui->progressBar->setValue(currentValue - 20);
    else ui->progressBar->setValue(currentValue + 20);
}