I downloaded C++ libJSON from this link:
And they suggest me to use it as a library. How can I create library using the code they have provided?
you must have installed g++ and make in console/terminal just compile it type make, it will produce libjson.a which is static libary. When you create you C/C++ program you can link it with it g++ -l libjson.a
and in your code include libJSON.h header file.
#include "libJSON.h"
and you can use all functions from that header file.
On windows you must Install MinGW (GNU utilities for Windows), or IDE like DevC++ or Code::Blocks (Code::Blocks use MinGW). You can also use Cygwin unix like environment for windows (but when you compile file in cygwin you can run it only in Cygwin)
In Code::Blocks when you create project you can set additinal library which will be linked with your executable.
i was trying to compile libjson 7.6.1 for Visual Studio 2010. And was facing some difficulties in compiling it. What i did was
Download Libjson
open libjson.vcproj and goto line 240. You will find a missing ">". Type it in and save the file.
Now this can be used to build dynamic and static lib.
A simple thing wasted my couple of hours. Hope it saves some of yours.
This solution also works for more recent versions of Visual studio (e.g. 2015) which otherwise fail to complete the conversion to the mare recent project format.
Related
I'm a big fan of StackOverflow because you always have answers for problems, and now is my chance to get advance of it Ö!
I'm trying to use a library which I got in the Internet, its OZCollide. Its suppossed to be crossplatform as it says in its website "Cross-platform, works on Windows, Linux and Macintosh, in fact any platform supporting VisualStudio 6/7 or gcc"
I got all the .h and .cpp, compile them with MinGW as objects (.o) and then link them all using ar. But the problem is when I include and use the library on my project (QT & MinGW) it throws "undefined reference".
I thought the problem could be that library examples only uses Visual Studio, so the library coulnd't be compiled for MinGW, but the website tells other story.
Thanks for your time!
EDIT: Okay I have managed to compile it and use it moving to another computer and compiling makefile. The only one difference is that Computer A had Cygwing and MinGW installed (with Cygwin set up in Windows path) and Computer B only had MinGW.
So I guess the problem was Makefile calling for g++ and Cygwin g++ got called instead of MinGW g++??
If I'm right, whats the difference between Cygwin and MinGW?
if you have experience with CMake, create your own CMakeLists file and import/link this libraries against your project. In this way, you can create projects for MinGW/MSVC/Linux/etc.
Here you'll find a good start with CMake http://www.cmake.org/cmake-tutorial/
I am trying to install kde-connect following this.
Although my kubuntu version is 14.04, I wanted to compile them so that I can have the latest version. But when I followed the instructions to compile, i get the following error.
-- Found Qt-Version 5.2.1 (using /usr/bin/qmake)
CMake Error: The following variables are used in this project, but they are set to NOTFOUND.
Please set them or make sure they are set and tested correctly in the CMake files:
QT_QT_INCLUDE_DIR
used as include directory in directory /home/vinaychandra/Downloads/t/CMakeFiles/CMakeTmp
CMake Error: Internal CMake error, TryCompile configure of cmake failed
CMake Error at /usr/share/kde4/apps/cmake/modules/FindKDE4Internal.cmake:1311 (message):
Unable to compile a basic Qt application. Qt has not been found correctly.
Call Stack (most recent call first):
/usr/share/cmake-2.8/Modules/FindKDE4.cmake:95 (find_package)
CMakeLists.txt:7 (find_package)
Please point out how to correct this.
I have tried giving -DQT_QT_INCLUDE_DIR=/usr/share/qt4/
then it tells that You must build your code with position independent code if Qt was built with -reduce-relocations.
Your cmake by default uses a different QT version.
So, you must explicitly tell him which version of QT he have to use for this job.
This one
-DQT_QT_INCLUDE_DIR=/usr/share/qt4/
Is wrong because you mustn't give QT position explicitly.
All you need is to use the right qmake.
So, give'em this flag and you'll be happy!
-DQT_QMAKE_EXECUTABLE=/usr/bin/qmake-qt4
Since most of kde applications are not ported to Qt5, you need Qt4.x for building kdeconnect(don't know x, mine is 4.8.6).
Also Qt4 installer is not available (I think !), so you have to build it also from source. Building Qt4 is quite easy, just download the source and run the usual commands.
After building it, it qmake name will be qmake-qt4 in /usr/bin.
So for building kdeconnect, first run its cmake, then a Cmaketextcache.txt file will form.
In that change the path of qmake (i.e somewhere written /usr/bin/qmake to /usr/bin/qmake-qt4) and also the path of qt include dir to (I think /usr/include/qt5 to /usr/include/qt4), and run the cmake again.
If some packages are missing, then you have to install it.
But with the above changes, you will get a make file to install it.
Unfortunately, the cited documentation is lagging behind the current state of kdeconnect. I ran into similar problems but I managed to solve them by installing the following required packages from the Kubuntu repositories:
sshfs
libfakekey-dev
libxtst-dev
libqca2-dev
libqjson-dev
I trust these are all of them. I installed kdeconnect from the latest git commit and it seems to run fine.
This answer comes a bit late, but this is the first Google search result for the question. In systems with qtchooser (Kubuntu, Ubuntu at least), this can be fixed by running first:
export QT_SELECT=qt4
This makes all of the Qt build tools to default to the Qt4 version instead of Qt5. You can check which Qt version is active by running:
qmake --version
Try kde connect install on ubuntu: https://fazlerabbi37.github.io/blogs/install_kde_connect_in_ubuntu_18.04.html
(in 18.04 & 19.04 it works with simple sudo apt install kdeconnect
Install kde connect on android device (google play store is where I installed from)
Invoke kde connect from desktop
Invoke kde connect from android and search device.
Your ubuntu will be found / initiating a search from desktop results in android phone pulled up for pairing
Accept pairing request
Provide access to folders
Try clicking on a video/image file for transfer
I could see the new file transferring in /Downloads folder of desktop
allowing/disallowing desktop to access sms, notifications etc are now a choice
Note: Pl treat this with pinch of salt. This appears very simple, effective for a main reason it worked for me in no time.
I have a prebuilt version of netcdf Library which I've downloaded from the Unidata website,
Now I am trying to link this Library to Qt 5, to use it in my Qt project. So I looked for some solutions in the internet and I found that I should add these lines to my Project.pro :
LIBS += -LC:/netcdf/lib -lnetcdf
INCLUDEPATH += C:/netcdf/include
But after runing the project, it doesn't work, so I rerun it with the debuger and it shows me this Message Box (titled "executable Failed") : During startup program exited with code 0xc0000135
Please help !
The pre-built libraries are built using Microsoft Visual Studio. As I recall, the C/C++ compiler the Qt SDK uses on Windows is a mingw-variant of gcc. I am not certain if the pre-built netcdf libraries are compatible with the mingw runtime, but it is usually not a good idea to mix C runtimes anyways.
I'm assuming you are using Qt Creator; if so, then it may be easier than you think to compile the netcdf-c libraries yourself. Because the netcdf-c project uses CMake, you will be able to open it as a project in Qt Creator.
Prerequisites
You will need the following:
cmake: http://cmake.org
netcdf-c source code: http://github.com/Unidata/netcdf-c/releases
NetCDF Dependencies
Note that you will need to install the following dependencies first, depending on the functionality you want from the netcdf library.
NetCDF4 support requires libhdf5 and libhdf5_hl, both provided by the hdf5 package available from http://www.hdfgroup.org.
DAP support requires libcurl. Google should be able to help you find this.
If you do not need these capabilities, you'll be fine with a straight netcdf-classic install.
Opening netcdf-c as a project in Qt Creator
Launch Qt Creator
Go to file->open project
Navigate to the netcdf-c source directory and open the CMakeLists.txt file.
This will load the netcdf source as a new project in Qt Creator. At this point it should be pretty straight forward to compile netcdf and install it somewhere on your system to use with your project.
Incorrect Assumption
If my assumption that you are using Qt Creator is wrong, this is all still possible from the command line; it will be, however, a little more involved.
I used 4.7.2 for the past months. Now I downloaded 4.7.3. Now I am searching to type "configure -static". But I don't know where the hell "the qt path". Can anybody shed a light on this issue.
Download the source package here. Download and install your favorite perl distribution. I must warn you that Strawberry perl comes with its own toolchain and that may get used instead of the MinGW you downloaded. Use ActivePerl if you don't want any trouble, or build it yourself.
Unzip it to say, C:\Qt-source so that there is a configure.exe in C:\Qt-source
Open the toolchain's command prompt
a) If you're using the Visual Studio compiler, search in the "start" menu for a CMD shortcut in the Visual Studio folder. The Windows SDK also has this shortcut.
b) If you're using MinGW, either use the accompanying mingwvars.cmd, or open a command prompt, (Run->"cmd.exe") and type set PATH=C:\path\to\mingw\bin;%PATH%. Try gcc -v to see if it can be found.
Make a build directory, preferable something like C:\Qt. Do set QTPATH=C:\Qt and set PATH=C:\Qt\bin;%PATH% and cd C:\Qt, and type:
..\Qt-source\configure -static
After configure finishes, you'll either have to type nmake (Visual Studio) or mingw32-make.
Go do something else, because it will take a while.
Some tips that result from my experience, and add a bit more to the answer of rubenv:
Pass the install directory as a flag of the configure; be sure to choose a different directory from the one where you have stored a non-static version of Qt!
Some modules will likely cause you troubles when compiling statically because you need to resolve the dependencies statically; one example is webkit, so if you don't need it be sure to disable it
It is generally not a good idea to build the debug symbols into a static library, so I normally debug with the dynamic version, and use the static Qt to generate releases only.
Therefore, my configure looks something like this:
configure -static -prefix C:\Qt\4.8.6_static -no-webkit -release
I am using qt 4.5
I have created a project and I want to compile on visual studio 2008 for windows mobile 6.0
So I have created the project files doing this:
D:\Projects\Phone_PDA\Phone_PDA>set QMAKESPEC=win32-msvc2008
D:\Projects\Phone_PDA\Phone_PDA>qmake -tp vc
The VS project was created. However, when I try and compile I get this error:
LINK : fatal error LNK1181: cannot open input file 'c:\Qt\qt\lib\qtmaind.lib'
However, when I check my librarys and includes under project properties in visual studio. I have this:
Additional Include Directories
c:\Qt\qt\include\QtCore
c:\Qt\qt\include\QtGui
c:\Qt\qt\include
c:\Qt\qt\include\ActiveQt
debug
c:\Qt\qt\mkspecs\win32-msvc2008
Additional Library Directories
c:\Qt\qt\lib
Additional Dependencies
c:\Qt\qt\lib\qtmaind.lib
c:\Qt\qt\lib\QtGuid4.lib
c:\Qt\qt\lib\QtCored4.lib
However, when I browse to the directory c:\Qt\qt\lib all I have is:
qtmain.prl and qtmaind.prl
However, I don't have qtmaind.lib or qtmain.lib
Many thanks for any suggestions,
Are you sure you are using the correct QMAKESPEC?
I would think you would need to use wince*-msvc2008
See Qt: Supported Platforms
Open the Visual Studio command prompt (you can find a shortcut in the start menu). It has all the appropriate environment variables set. Go to C:\Qt\20****\qt. Type configure and then nmake.
Did you download the source distribution? If so you would need to compile Qt before you get the libs.
See:
http://doc.qtsoftware.com/4.5/install-win.html
http://doc.qtsoftware.com/4.5/install-wince.html
My commercial version comes precompiled. If I remember correctly, when I used the open source version I needed to compile everything myself.
First you have to configure the Qt to your machine to get the libs! It will takes several minutes. Follow the steps in: http://portfolio.delinkx.com/files/Qt.pdf
in properties -> linker -> input
remove ANY path for qt libraries such qtmaind.lib
sometime you need remove :
/SUBSYSTEM:WINDOWS%40QMAKE_SUBSYSTEM_SUFFIX%40) from the VS project (under Properties --> Linker --> Command Line).
this is known BUG in VS addin