Cannot open include file: 'QtNetwork': No such file or directory

[Aminmlp]

I use vs 2017 c++. I can use qt without any problem, but when I include QtNetwork, i get an error ???

#include <QtCore> // work
#include <QtNetwork> //not work ??

second #include does not work ?

both of then are in the same folder.

[Bonnie]

add

QT += network

to your .pro file

[Aminmlp]

for example, it works in this way
"#include <QtNetwork\QTcpsocket>"

[Aminmlp]

I do not know why my VS can not open some Qt modules, for example:
#include <QtGui> // no error
#include <Qt3DCore> error
?????

[jsulm]

@Aminmlp Do you have

QT += 3dcore

in your pro file?

[Aminmlp]

where is this file?

[jsulm]

@Aminmlp Well, since you're using Visual Studio and not QtCreator you have to check how it is done in Visua Studio. I don't use Visual Studio but it looks like it is in "Qt Modules" tab - see https://doc.qt.io/qtvstools/qtvstools-managing-projects.html

Background: Qt is modular, that's why you need explicitly activate modules you want to use. This way you can reduce dependencies of your app.

[Aminmlp]

I find the .pro file and add QT+= 3dcore but does not work

[jsulm]

@Aminmlp After editing pro file you need to run qmake and rebuild

[Aminmlp]

problem solved. this link https://doc.qt.io/qtvstools/qtvstools-managing-projects.html solved my problem. thanks