how to add library(qmqtt.h) in qmqtt client for windows

raven-worx

@shravani
You need to be more specific to be able to help, since this can have many causes.
Maybe you just need to rerun qmake to update the makefiles?
Show the directory structure and your .pro file.

shravani

hi,
this is my .pro file
and my code is inthis( https://github.com/wuming123057/qmqtt-client) link.
the library i added is https://github.com/emqtt/qmqtt

QT += core gui network

greaterThan(QT_MAJOR_VERSION, 4): QT += widgets

CONFIG += c++11
CONFIG+= NO_UNIT_TESTS
TARGET = qmqtt-client
TEMPLATE = app

#NOTICE: add DYLD_LIBRARY_PATH to build environment.
INCLUDEPATH += C:\Qt\qmqtt-master\src
LIBS += -LC:\Qt\qmqtt-master\src -lqmqtt

SOURCES += main.cpp
mainwindow.cpp
connform.cpp
pubform.cpp
subform.cpp

HEADERS += mainwindow.h
connform.h
pubform.h
subform.h
mqttform.h

FORMS += mainwindow.ui
connform.ui
pubform.ui
subform.ui

im getting error:
cannot find -lmqtt
returned 1 exit status

Fuel

which name has the library in this path C:\Qt\qmqtt-master\src ?

raven-worx

@shravani said in how to add library(qmqtt.h) in qmqtt client for windows:

INCLUDEPATH += C:\Qt\qmqtt-master\src

should point to the sources of qmqtt (specifically where qmqtt.h is placed in)

LIBS += -LC:\Qt\qmqtt-master\src -lqmqtt

Also you need to build qmqtt beforehand. -L should point to the path of the library (.lib) you built

shravani

thank you,
i will try building the qmqtt.

shravani

@raven-worx
hi,
i tried building the library(i got "could not find executable please specify one" dialog box) there is no .dll or .lib or .so file in build folder.
in build it created 3 folders(.moc,.obj,.pch).could you please tell me how to generate .lib file

jsulm

@shravani Can you explain what exactly you did?

shravani

@jsulm

from here https://github.com/emqtt/qmqtt i downloaded zip file.in that src/mqtt mqtt.pro i built using qt.but that library not generating any .lib files.
(as u told i need to build qmqtt beforehand. -L should point to the path of the library (.lib) you built.)

jsulm

@shravani What I wanted to know was: how exactly did you build? What steps did you execute?
"built using qt" - what does this mean? Qt does not build anything. Do you mean you used QtCreator or qmake?
Can you also post the build log?

shravani

@jsulm
i used qt creator.i just opened .pro file (src/mqtt/mqtt.pro from above link)using qtcreator and build all.

jsulm

@shravani Can you post the build log?

shravani

@jsulm
when i click on build all one dialog box came like below.but in build folder(build-abc-Desktop_Qt_5_8_1_MinGW_32bit-Debug) .lib file not generated only 3 folders(.moc, .obj , .pch) created .!!

jsulm

@shravani It looks like you're clicking on Run not on Build. Since mqtt is a lib you cannot execute it. And again: can you post the build log?

shravani

@jsulm
sorry ,i can only post what i got after building in build folder.!

jsulm

@shravani Why can't you post the build log? You have it in QtCreator. The screen-shots you posted do not help.

raven-worx

@shravani
got the folder where you donwloaded qmqtt (where the qmqtt.pro resides) and and execute the following:

qmake
nmake (for Visual Studio compiler) or mingw32-make (for mingw)

thats it. No QtCreator needed.
Then the .dll and corresponding .lib (MSVC) or .a (mingw32) file will be created in the output folder.

shravani

@raven-worx
thank you,
im new to qt could you please tell me how to execute qmake and mingw32-make in windows?

raven-worx

@shravani
open a console window and execute "qmake" let it finished and afterwards execute one of the two (the correct one corresponding to your used compiler!) make commands for building.

Make sure that the executable can be found by the system (add the paths to the PATH environment variable)
But those a pretty basics. Probably you should go on reading some learning material first before trying to build a software which is based on a 3rd party library.

shravani

@raven-worx
can u give any link to read? and where .lib will be created? in same folder?

raven-worx

@shravani
Getting started.
Probably you should consider buying a book about Qt also