How to check if a resource exists?

SPlatten

I'm trying to defeat the QML messages that come up when an image isn't present or doesn't exist.

In my C++ function I have written a helper function:

QString Manager::checkPath(QString path) {
    bool valid = false;
    if ( path.length() > 0 && path.indexOf(".") > 0 ) {
        const String QRCprefix("qrc:");
        if ( path.startsWith(QRCprefix) != true ) {
            const QString imgsPath("/images/");
            if ( path.startsWith(imgsPath) != true ) {
              path += imgsPath;
            }
            path = QRCprefix + path;
        }
        valid = QFile::exists(path);
    }
    return (valid == true) ? path : "";
}

I'm calling this from the QML, as an example I can see in Qt Creator a valid reference is passed:

qrc:/images/ImageViewer/viewer_camera_rear2_off.png

However, when it gets to call QFile::exists(), this returns false. I've read elsewhere on these forums that QFile::exists can be used on resources, however my findings suggest either I'm doing something wrong or this isn't the case.

Can anyone tell me?

sierdzio

Last resort is to check ":/images" but I suspect it to fail as well.

Can you paste here the relevant line from your .qrc file?

sierdzio

@SPlatten said in How to check if a resource exists?:

qrc:

QFile does not understand this part. In order for QFile to get it, you need a different URL:

qrc:///images/ImageViewer/viewer_camera_rear2_off.png

SPlatten

No difference, still returns false.

Have tried:

qrc:/images/ImageViewer/viewer_camera_rear2_off.png
qrc://images/ImageViewer/viewer_camera_rear2_off.png
qrc:///images/ImageViewer/viewer_camera_rear2_off.png

All return false, yet the path is valid.

sierdzio

Last resort is to check ":/images" but I suspect it to fail as well.

Can you paste here the relevant line from your .qrc file?

SPlatten

I am trying that now, funny enough I thought the same, refreshed and saw your suggestion.

SPlatten

:/images/ImageViewer/viewer_camera_rear2_off.png

Works! And now QFile::exists returns true, thank you!

sierdzio

Nice! Happy coding