How do I create a simple Qt console application in C

Question

I was trying to create a simple console application to try out Qt s XML parser  I started a project in VS2008 and got this template   int main int argc  char  argv          QCoreApplication a argc  argv        return a exec        Since I don t need event processing  I was wondering whether I may get into trouble if I neglect to create a QCoreApplication and running the event loop  The docs state that it s recommended in most cases   For the sake of curiosity however  I am wondering how could I make some generic task execute on the event loop and then terminate the application  I was unable to google a relevant example

User · Answer

I managed to create a simple console  hello world  with QT Creator  used creator 2 4 1 and QT 4 8 0 on windows 7  two ways to do this   Plain C    do the following   File- new file project under projects select   other Project select  Plain C   Project   enter project name 5 Targets select Desktop  tick it  project managment just click next you can use c   commands as normal c      or   QT Console   File- new file project under projects select   other Project select QT Console Application         Targets select Desktop  tick it  project managment just click next add the following lines  all the C   includes you need  add    include  iostream    add   using namespace std    after QCoreApplication a int argc  cghar  argv    10 add variables  and your program code     example   for QT console   hello world   file  - new file project  project name    other projects - QT Console Application  Targets select  Desktop   project management - next  code        include  lt QtCore QCoreApplication gt       include  lt iostream gt      using namespace std      int main int argc  char  argv               QCoreApplication a argc  argv        cout lt  lt   hello world        return a exec             ctrl -R to run   compilers used for above MSVC 2010  QT SDK    and minGW QT SDK   hope this helps someone  As  I have just started to use QT recently and also searched  the Www for info and examples to get started with simple examples still searching

User · Answer

Don t forget to add the   CONFIG    console    flag in the qmake  pro file   For the rest is just using some of Qt classes   One way I use it is to spawn processes cross-platform

User · Answer

Here is one simple way you could structure an application if you want an event loop running      main cpp  include  lt QtCore gt   class Task   public QObject       Q OBJECT public      Task QObject  parent   0    QObject parent      public slots      void run                    Do processing here          emit finished           signals      void finished         include  main moc   int main int argc  char  argv          QCoreApplication a argc  argv           Task parented to the application so that it        will be deleted by the application      Task  task   new Task  amp a           This will cause the application to exit when        the task signals finished          QObject  connect task  SIGNAL finished      amp a  SLOT quit              This will run the task from the application event loop      QTimer  singleShot 0  task  SLOT run           return a exec

User · Answer

You can call QCoreApplication  exit 0  to exit with code 0

User · Answer

You don t need the QCoreApplication at all  just include your Qt objects as you would other objects  for example    include  lt QtCore gt   int main         QVector lt int gt  a     Qt object      for  int i 0  i lt 10  i                  a append i                 manipulate a here         return 0

User · Answer

You could fire an event into the quit   slot of your application even without connect    This way  the event-loop does at least one turn and should process the events within your main  -logic    include  lt QCoreApplication gt   include  lt QTimer gt   int main int argc  char  argv          QCoreApplication app  argc  argv            do your thing  once      QTimer  singleShot  0   amp app   amp QCoreApplication  quit        return app exec        Don t forget to place CONFIG    console in your  pro-file  or set consoleApplication  true in your  qbs Project CppApplication

User · Answer

Had the same problem  found some videos on Youtube  So here is an even simpler suggestion  This is all the code you need    include  lt QDebug gt   int main int argc  char  argv           qDebug    lt  lt  Hello World  lt  lt  endl     return 0      The above code comes from Qt5 Tutorial  Building a simple Console application by  Dominique Thiebaut  http   www youtube com watch v 1 aF6o6t-J4

[c++] How do I create a simple Qt console application in C++?

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