QDataStream to QByteArray and ViceVersa

[ChrisW67]

Thanks, ChrisW67 for a detailed explanation, but I have a different use case.

In my code, I have to pass a QByteArray to a generic API which is taking QDataStream as a parameter. In that API I need to again deserialize the QDataStream to QByteArray.

A QDataStream object is not the data, nor does it contain the data, it merely decodes a set of bytes provided to it. You need to construct a correct set of bytes to provide it.

Assuming you are expecting the "other end" to receive exactly the bytes you have in your code:

QByteArray payload = QByteArray::fromHex("0200000008305370FFFFFF630500008E");
// Serialise it using QDataStream
QBuffer buffer;
buffer.open(QIODevice::WriteOnly);
QDataStream out(&buffer);
out << payload;
buffer.close();

QByteArray payload = QByteArray::fromHex("0200000008305370FFFFFF630500008E");
// Serialise it using QDataStream
QBuffer buffer;
buffer.open(QIODevice::WriteOnly);
QDataStream out(&buffer);
out << payload;
buffer.close();

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Then buffer contains the bytes you need to transmit, and

if (buffer.open(QIODevice::ReadOnly)) {
  QDataStream passThis(&buffer);
  readContainer(passThis); 
}

if (buffer.open(QIODevice::ReadOnly)) {
  QDataStream passThis(&buffer);
  readContainer(passThis); 
}

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should get the bytes there.