Qt how to open a file in current dir ? or what's wrong with this?
I'm trying to open an xml file in the current location of the executable
QString path = QDir::currentPath();
path.append("/acc.xml");
QFile f开发者_如何学Goile(path);
if(!file.open(QIODevice::ReadOnly))
{
insertItem("IO ERR");
}
When I run it from Qt creator, everything works.
currentPath()
returns the path to the executable's folderWhen I go to
project-build-desktop/
folder and try to run it manuallycurrentPath()
returns/home/user/Documents
EDIT
also tried with same results:
Qt::current().path();
Qt::current().absolutePath();
Try to use QCoreApplication::applicationDirPath() instead of QDir::currentPath().
For details see http://doc.qt.io/qt-5/qcoreapplication.html#applicationDirPath
Check the returned value of QDir::currentPath()
. I think when you run from Qt Creator, it returns the path where the project file (*.pro) is located. When you run from outside, you get path of the binary.
Edit
I never worked with Linux. However, you can try other functions/combinations from QDir
:
- QDir::current().path()
- QDir::current().absolutePath()
etc.
To open a file in the current directory, you simply call QFile constructor
I tested this on my Linux machine and it works
#include <QtCore>
int main(int argc, char** argv){
QFile some_file("test.xml");
if(!some_file.open(QIODevice::ReadOnly | QIODevice::Text)){
qDebug() << "Unable to open file";
} else {
qDebug() << "File open successfully";
}
exit(-1);
}
I run ./TestQFile and if there is a test.xml in the current directory, it works.
UPDATE: I notice that the wording of your question says that you want the file in the same directory as the executable, this can be done as follow:
// Getting directory of the executable
QFileInfo exec_fileinfo(argv[0]);
qDebug() << "Executable is in" << exec_fileinfo.absolutePath();
UPDATE 2: Under the project panel of QtCreator, there is a field for Working Directory. This is the directory that is returned by QDir::currentPath() if you are running it via QtCreator.
I found this discussion while searching for a similar solution. I think that the most portable way of opening an external file that has a fixed name (and no dialogs and the user are involved) is to use the Resource System.
In my case I created a new resource file with the prefix /config
and added the file (called settings.xml
). Inside the code, I don't need to use any path functions at all. I use the resource system instead. Thus a call like QFile file(":/config/settings.xml")
works fine. Using QT creator 2.0.1 and QT 4.7 on Windows.
My tip is this : name of the file + the absolute path to it before opening it. For that I call the method applicationDirPath
on our QCoreApplication
object (the a
object in my case), which returns us the path to the executable of the application. No need going through the argv
array. That's it and works
int main(int argc, char *argv[]) {
QCoreApplication a(argc, argv);
const QString fileName = "someJsonFile.JSON";
const QString currentExecDir = a.applicationDirPath();
QFile myFile(currentExecDir + '/' + fileName);
if (myFile.open(QIODevice::ReadOnly)) {
qDebug()<< "The file "<< fileName<< " has been opened successfully";
}
else {
qDebug()<< "Failed to open file "<< fileName<< " in "<< currentExecDir;
}
return a.exec();
}
NOTE
Please see the Qt docs for the applicationDirPath
method, because it assumes that the current directory has not been changed by the application
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