C++ Qt - QTcpSocket - File not found

c++ qt qtcpsocket

15,152

You need

QT += network

in your .pro file. Otherwise the module in which those headers are defined/libraries are built won't be loaded.

15,152

Author by

Béatrice Moissinac

Graduate Student in Machine Learning at Oregon State University

Updated on June 24, 2022

Comments

Béatrice Moissinac almost 2 years
I am using Qt and QTcpSocket to create a small chat client/server application.

When I compile my code, the compiler returns the following error:
```
main.cpp:3:22: fatal error: QTcpSocket: No such file or directory
```
This refers to #include <QTcpSocket>.

Where is this library located and how can I install it?
Béatrice Moissinac over 11 years

Indeed, you are right. I still get main.cpp:3:22: fatal error: QTcpSocket: No such file or directory. Ah! That's funny! So I modify my .pro, save, and run qmake -project, qmake and make in my terminal, and it changes my .pro back to before!
Béatrice Moissinac over 11 years

I don't have this problem if I compile inside Qt Creator. Closing and restarting it does not affect this issue. Why are my changes not accepted by qmake -project?
Matt Phillips over 11 years

@Bibi541 What? .pro files aren't auto-generated in any way that I've ever heard. Something isn't right--you didn't forget to save changes or something simple like that did you?
Béatrice Moissinac over 11 years

What is different when I compile it with Qt Creator? Is it possible that the Makefile does not get updated?
Matt Phillips over 11 years

@Bibi541 I almost always use QtCreator, but when I have compiled/run qmake from the command line, I've never seen what you just described. I think running qmake should always generate a new makefile--that's the point right? Also auto-generated are the .pro.user files, you didn't get mixed up with one of those somehow did you?
Béatrice Moissinac over 11 years

No, because I modified my .pro in Qt Creator, which only shows the .pro in the project. There is no way I changed .pro.user instead. Strange...
Béatrice Moissinac over 11 years

The only reason why I was typing the command line is because somehow my images where not loading when running it with QtCreator, but loading when doing it by hand. Well, I will compile with QtCreator for now, and if I need to load my images, I guess I will come back to stackoverflow and ask :)
Matt Phillips over 11 years

@Bibi541 Yes these kinds of issues with Qt pop up from time to time and can be pretty annoying. Good luck!