Qt Image from resource file

Question

I'm trying to insert an image to my program via resource file, which is like:

<RCC>
    <qresource prefix="/">
        <file>green.png</file>
        <file>other files</file>
    </qresource>
</RCC>

and when I'm trying to load it using QImage or QPixmap, like:

QImage *green = new QImage(":/green.png");
if(green->isNull()) qDebug("null");

I always see that null message, indicating that I'm doing something wrong. One solution may be using absolute path like

"C:\\Users\\user\\Documents\\project\\green.png",

which works of course, but I'd prefer implement it using resource file. Could you please give me some advice?

Answer 1

All this will work if your png files are located in the same folder as .pro, .qrc, and .cpp files of your project.

Usually it is convenient to put all images to special subfolder Resources, for example. Then in .qrc the line will look like:

<file>Resources/green.png</file>

And in .cpp file:

QImage *green = new QImage(":/Resources/green.png");

Answer 2

添加资源文件后还记得运行qmake吗？

Answer 3

First of all, you need to create a .qrc file and add image folder to it

1. (image folder must be contained inside of the project folder)
2. Right-click on the project file
3. Add New
4. Qt
5. Qt Resource File press Choose and do other steps
6. after opening .qrc file you must press Add > Add Prefix > change prefix name if you want
7. again Add > Add File > and choose your images

8. then go to mainwindow.cpp (in my project ) file and call the images as below code

   • in my case the icon folder is Playericons

ui->play->setIcon(QIcon(":/Playericons/icons8-pause-30.png"));