I'm using a QProgressDialog with the limits (0, 0) to show something during a sqlite query and preparing the results to show. The QProgressDialog window stays in blank all the time, not matter if the process took 1 second or minute. My code is something like:



Qt Code: 
  1. QProgressDialog dialog(this);
  2.     dialog.setLabelText("Updating");
  3.     dialog.setMinimun(0)
  4.     dialog.setMaximum(0);
  5.     dialog.show();
  6.     try
  7.     {
  8.         // here I call a function that executes a sql query to a sqlite database and then updates the whole interface with the result.
  9.         dialog.accept();
  10.     }
  11.     catch (QString e)
  12.     {
  13.         QMessageBox::critical(this, "Error - " + qApp->applicationName(), e);
  14.         qApp->exit(1);
  15.     }
To copy to clipboard, switch view to plain text mode 

Reading other post I have seen that in cases of a long during process is better to use another thread instead of the main one. It's this correct? Can I block the program during the process so the user can't interact with it when using another thread?