Question

I wan’t to display a message, only on the first usage of application, i.e. a piece of code should be executed only once, when application is first time invoked. I tried using QSettings, but couldn’t work out any way.

if(firstTime)
   {
      //do something!
   }

Answer 1

Just check QSettings for some value at launch. If it doesn’t exist, then its a first launch. After that, set the variable so it will be found each subsequent load.

In PyQt4 it would look like this (I am sure you can translate to C++):

settings = QSettings("foo.plist", QSettings.NativeFormat)

if not settings.contains('hasLaunched'):
    # this is our first time! Weee

# no matter what, set the value for the future
settings.setValue('hasLaunched', 1)