QApplication: No such file or directory of Qt Classic error message

QApplication: No such file or directory of Qt Classic error message

This error message is usually the first example for a novice to open Qt programming when compiling Qt5's first application "Hello,World". All

It's easy to say.

# include

# include

Int main (int argc, char * argv [])

{

QApplication app (argc,argv)

QWidget * ww=new QWidget ()

Ww- > resize (300200)

Ww- > show ()

Return app.exec ()

}

A compilation result of the above error, which is called a depressed.

As a matter of fact, a novice can solve the problem on his own by paying attention to the hint. The method is also simple, that is, after performing the following two steps

Qmake-project

Qmake

Modify the hello.pro project file immediately and add a line of code as follows:

QT + = gui declarative or QT + = core gui widgets

After saving it, perform the last step: mingw32-make.exe

In this way, you can compile a distribution version of hello.exe in the release directory, note, not the debug directory.