使用QXmlQuery(Qt XQuery)时，如何绑定名称空间前缀? [英] How does one bind namespace prefixes when using QXmlQuery (Qt XQuery)?

问题描述

我正在尝试使用QXmlQuery对具有声明的默认名称空间的文档执行XQuery表达式.

I'm attempting to use QXmlQuery to execute an XQuery expression against a document with a declared default namespace.

以供讨论:

<?xml version="1.0" encoding="UTF-8"?>
<root xmlns="http://namespace.com/ns1">
    <node1 attr1="hi"/>
</root>

现在，我要打开以下内容并查询该文档:

Now, I have the following to open and query against the document:

QFile temp("my.xml");
temp.open(QIODevice::ReadOnly | QIODevice::Text);

QXmlQuery query;
query.setFocus(&temp);

QXmlResultItems items;
query.setQuery("/root");

query.evaluateTo(&items);

在运行此命令时，"items"中永远都没有数据，因为文档已命名.当然，如果删除默认的名称空间声明，则"items"确实具有正确的数据，但是我没有那么奢侈.

In running this, 'items' never has data in it, since the document is namespaced. Of course, if I remove the default namespace declaration, 'items' does have the correct data, but I don't have that luxury.

我尝试将查询更改为:"/prefix:root"，并且Qt发出警告，如:

I've tried changing the query to: "/prefix:root", and Qt barks a warning like:

No namespace binding exists for the prefix prefix in prefix:root

因此，名称空间绑定确实存在！但是哪里?我看到了QXmlNamePool，但是它没有增变方法.我可以使用查询ala的池创建一个QXmlName:

So namespace binding does exist! But where? I see QXmlNamePool, but it has no mutator methods. I can create a QXmlName with the pool from the query ala:

QXmlName name(query.namePool(), "prefix", "http://namespace.com/ns1");

但是它并没有改变任何东西.我不知所措，我使用的其他工具箱都有简单的方法将前缀绑定到名称空间URI.

But it doesn't change anything. I'm at a loss, other toolkits I have used have simple methods to bind prefixes to namespace URIs.

推荐答案

我相信您是否可以将查询更改为

I believe if you would change your query to

...
QXmlResultItems items;
query.setQuery("declare default element namespace \"http://namespace.com/ns1\"; /root");
...

它应该返回数据.

希望这会有所帮助

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