QResource::registerResource with rccData instead rccFileName

[Christian Ehrlicher]

Simply read the content of your resource into a QByteArray and pass QByteArray::constData() to registerResource(). The internal logic knows how long the resource data is.

[LazyT]

Thanks for your answer, but this doesn't work.

For example:

QResource rcc(":/rcc/icons.rcc");
QByteArray ba = rcc.uncompressedData();
qDebug() << rcc.isValid() << QResource::registerResource(ba.constData());

Result: true false

[Christian Ehrlicher]

@LazyT said in QResource::registerResource with rccData instead rccFileName:

but this doesn't work.

Because you have to pass the content of the resource file - read it with QFile. It's meant to deal with external resource files.

[LazyT]

Makes no difference.

QResource and QFile shows the content of the RCC file, but register fails.

[Christian Ehrlicher]

Please show your code. How did you create the external resource file?

[LazyT]

Thanks for your patience.

The RCC was created with

rcc --binary icons.qrc -o icons.rcc

contains SVGs and works fine with the rccFileName variant.

QFile rcc("/tmp/icons.rcc");

if(rcc.open(QIODevice::ReadOnly))
{
	QByteArray ba = rcc.readAll();
	rcc.close();
	qDebug() << ba << QResource::registerResource(ba.constData());
}
else
{
	qDebug() << "RCC open failed";
}

Result is the content of the RCC file and false.

[Christian Ehrlicher]

@LazyT said in QResource::registerResource with rccData instead rccFileName:

QResource::registerResource(ba.constData());

registerResource() takes a const uchar *. You're passing a const char * which is not automatically convertible to a const uchar * but instead implicitly converted into a QString because you did not define QT_NO_CAST_FROM_ASCII which you should to avoid such errors.

[JonB]

@Christian-Ehrlicher Wow!!

[LazyT]

Hm,

DEFINES += QT_NO_CAST_FROM_ASCII

gives tons of "is private within this context" errors.

QResource::registerResource(reinterpret_cast<const uchar*>(ba.constData()));

results in true, but icons are not available because "qt.svg: Cannot open file 'xxx', because: No such file or directory".

I give up for today.

Thanks for your hints.

[Christian Ehrlicher]

@LazyT said in QResource::registerResource with rccData instead rccFileName:

gives tons of "is private within this context" errors.

Because you have a lot of implicit casts from char* to QString which are for sure not what you want.

but icons are not available because

Works fine for me:

<RCC>
    <qresource prefix="/">
        <file>stylesheet.qss</file>
        <file>icons/menuIndicatorChecked.png</file>
        <file>icons/menuIndicatorUnchecked.png</file>
        <file>icons/SimulationModeOnNormal.png</file>
        <file>icons/dashedline.png</file>
    </qresource>
</RCC>

int main(int argc, char *argv[])
{
QApplication app(argc, argv);
QFile f("style.rcc");
f.open(QIODevice::ReadOnly);
auto ba = f.readAll();
qDebug() << ba.size();
qDebug() << QResource::registerResource(reinterpret_cast<const uchar*>(ba.constData()));
QFile fRes(":/icons/menuIndicatorChecked.png");
qDebug() << fRes.exists() << fRes.isOpen() << fRes.readAll().size();
return 0;

-->

25888
true
true true 274

[LazyT]

The problem was

"Warning: The data must remain valid throughout the life of any QFile that may reference the resource data."

Moved the resource from the subroutine and it works now.

Thanks!