QXmlStreamWriter, namespace and prefix - c++

Question

I am new to XML and trying to write the following xml using QXmlStreamWriter :
<S:Envelope xmlns:S="url1">
<S:Body>
<ns2:name1 xmlns:ns2="url2">
..
So far I have tried:
sw.writeNamespace("url1", "S");
sw.writeStartElement("url1", "Envelope");
sw.writeStartElement("url1", "Body");
sw.writeStartElement("url2", "name1");
sw.writeNamespace("url2", "ns2");
but the result is not what I expect:
<S:Envelope xmlns:S="url1">
<S:Body>
<n1:name1 xmlns:n1="url2">
..
As specified in the documentation, the defaut prefix n1 is used instead of ns2.
If I swap the last 2 lines, I have:
<S:Envelope xmlns:S="url1">
<S:Body xmlns:ns2="url2">
<ns2:name1>
..
What am I doing wrong?

Answer 1

From the documentation of QXmlStreamWriter:
you can bypass the stream writer's namespace support and use overloaded methods that take a qualified name instead.
That is, use this overloaded method: QXmlStreamWriter::writeStartElement.
I suggest you to modify your code like that:
sw.writeNamespace("url1", "S");
sw.writeStartElement("url1", "Envelope");
sw.writeStartElement("url1", "Body");
sw.writeStartElement("ns2:name1");
sw.writeNamespace("url2", "ns2");
This produces the result you have stated as desired:
<S:Envelope xmlns:S="url1">
<S:Body>
<ns2:name1 xmlns:ns2="url2">