I have a project developed in QT 5.9.5, so C . I have an with a GUI and I want to describe the appereance of the widgets with an external global stylesheet. I'm working with QTCreator. I added a general file named "stylesheet.qss" and QTCreator put it into "Other files" directory. I have not created resources files. Only the qss file inside the "Other files" directory. To call the file, I write in the mainwindow.cpp (mainwindow is the user interface, mainwindow.ui) the following code:

QFile file(":/stylesheet.qss");
file.open(QIODevice::ReadWrite);
QTextStream in(&file);
QString text;
text = in.readAll();
file.close();
setStylesheet(text);

When I run the app, the application output give me the following problem:

QIODevice::read (QFile, ":/stylesheets.qss"): device not open

Instead, if I write:

QFile file("stylesheet.qss");

And also if I write:

file.open(QIODevice::ReadOnly);

the problem doesn't occur. However, in all the cases, the variable text is empty and I can't use stylesheet. Checking the file.errorString(), it gives:

"Unknown error"

and checking the file.error(), it gives:

0

Someone can suggest me a solution or another way to add a stylesheet to my app? Thank you, Marco

CodePudding user response：

1. add your .qss File in Resource(.qrc)

2. put this code that you want to add your qss in your program in main.cpp :

#include "mainwindow.h"

#include <QApplication>
#include <QFile>

int  main(int argc, char *argv[])
{
    QApplication  a(argc, argv);

    /**
     * Load the application style
     */
    QFile  styleFile(":/Style.qss");

    styleFile.open(QFile::ReadOnly);

    /**
     * Apply the loaded stylesheet
     */
    QString  style(styleFile.readAll());
    a.setStyleSheet(style);

    MainWindow  w;
    w.show();

    return a.exec();
}