blocks|key|2455146|text|不要在阅读器上使用任何“读”操作--正如你已经发现的那样，这会使它提前。使用对属性(如reader.HasValue和reader.Value+)的调用来检查内容。在对象浏览器中查找'XmlReader‘，您可以读取很多属性。|type|unstyled|depth|inlineStyleRanges|offset|length|style|CODE|entityRanges|data|2455147|编辑:我认为没有简单获取XML的简单方法，可能是因为当前节点本身可能不是有效的XML，例如XmlWhiteSpace、XmlText节点甚至XmlAttribute。|2455148|entityMap^0|17|F|1N|C|0|0^^$0|@$1|2|3|4|5|6|7|J|8|@$9|K|A|L|B|C]|$9|M|A|N|B|C]]|D|@]|E|$]]|$1|F|3|G|5|6|7|O|8|@]|D|@]|E|$]]|$1|H|3|-4|5|6|7|P|8|@]|D|@]|E|$]]]|I|$]]

Don't use any 'Read' operation on the reader- as you've discovered, this advances it. Use calls to properties such as <code>reader.HasValue</code> and <code>reader.Value</code> to inspect the contents. Look up 'XmlReader' in the object browser, there's quite a few properties you can read.

Edit: I don't think there's an easy way of simply getting the XML, possibly because the current node may not be valid XML on it's own, such as an XmlWhiteSpace, XmlText node or even an XmlAttribute.

blocks|key|1197365|text|实际上，ReadSubtree将返回一个“包装”原始阅读器的读取器。因此，阅读新的，最终也将推进原来的。您必须将XmlReader看作是一个前进的唯一读取器，它根本不能返回。至于您的场景，您可以向读者询问输入文件中的位置，而不是试图记住XML的一部分。只要把它转换到IXmlLineInfo接口，它就有了返回线和位置的方法。使用它，您可以记住一些起始位置(在所讨论的元素之前)，然后记住错误的结束位置。然后将该部分从intput文件中读取为纯文本。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1197366|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

Actually ReadSubtree will return a reader which "wraps" the original reader. So reading through the new one will end up advancing the original one as well.
You must consider XmlReader as a forward only reader, it simply can't go back.
As for your scenario, instead of trying to remember part of the XML you can ask the reader for the position in the input file. Just cast it to IXmlLineInfo interface, it has methods to return line and position. Using this you could remember some starting position (before the element in question) and then the end position of the error. And then read that part from the intput file as a plain text.

blocks|key|1198428|text|事实上，尽管Vitek是对的，海伦娜·库普科娃在https://msdn.microsoft.com/en-us/library/aa302292.aspx上发表了一个精巧的XML阅读器。这允许使用缓存向后移动。|type|unstyled|depth|inlineStyleRanges|entityRanges|offset|length|data|1198429|entityMap|0|LINK|mutability|MUTABLE|url|https://msdn.microsoft.com/en-us/library/aa302292.aspx^0|O|1I|0|0^^$0|@$1|2|3|4|5|6|7|L|8|@]|9|@$A|M|B|N|1|O]]|C|$]]|$1|D|3|-4|5|6|7|P|8|@]|9|@]|C|$]]]|E|$F|$5|G|H|I|C|$J|K]]]]

In fact, although Vitek Karas MSFT is right, Helena Kupkova published a deft little XML Bookmark Reader on <a href="https://msdn.microsoft.com/en-us/library/aa302292.aspx" rel="nofollow">https://msdn.microsoft.com/en-us/library/aa302292.aspx</a>. This enables going backwards using caching.

blocks|key|2500660|text|另一个想法是:读取外部XML+(这会提升读取器)，然后从这个XML创建一个新的读取器，它允许您“返回”并处理当前节点的元素。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2500661|while+(r.ReadToFollowing("ParentNode"))
{
++++parentXml+=+r.ReadOuterXml();

++++//since+ReadOuterXml()+advances+the+reader+to+the+next+parent+node,+create+a+new+reader+to+read+the+remaining+elements+of+the+current+parent
++++XmlReader+r2+=+XmlReader.Create(new+StringReader(parentXml));
++++r2.ReadToFollowing("ChildNode");
++++childValue+=+r2.ReadElementContentAsString();
++++r2.Close();
}++++++++++++++++++|code-block|syntax|javascript|2500662|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Another idea: read the outer XML (which advances the reader), then create a new reader from this XML which allows you to "go back" and process the elements of the current node.

<pre><code>while (r.ReadToFollowing("ParentNode"))
{
 parentXml = r.ReadOuterXml();

 //since ReadOuterXml() advances the reader to the next parent node, create a new reader to read the remaining elements of the current parent
 XmlReader r2 = XmlReader.Create(new StringReader(parentXml));
 r2.ReadToFollowing("ChildNode");
 childValue = r2.ReadElementContentAsString();
 r2.Close();
} 
</code></pre>

blocks|key|1197432|text|我所做的只是将元素读取到一个XmlDocument中，然后读取它。在我的例子中，我必须将流文档转换为HTML。我必须读取一个内部元素来为父HTML元素分配一个“样式”。|type|unstyled|depth|inlineStyleRanges|entityRanges|data|1197433|entityMap^0|0^^$0|@$1|2|3|4|5|6|7|D|8|@]|9|@]|A|$]]|$1|B|3|-4|5|6|7|E|8|@]|9|@]|A|$]]]|C|$]]

What I did was read just the element into an XmlDocument, and read that instead. In my case, I had to convert a flow document to HTML. I had to read a inner element to assign a "style" to the parent HTML element.

blocks|key|2455259|text|与ReadSubtree类似的东西|type|unstyled|depth|inlineStyleRanges|entityRanges|data|2455260|using+(XmlReader+reader+=+XmlReader.Create(new+StringReader(xml)))
++++++++++++++++++++++++++++++++{
++++++++++++++++++++++++++++++++++++reader.MoveToContent();
++++++++++++++++++++++++++++++++++++while+(reader.Read())
++++++++++++++++++++++++++++++++++++{
++++++++++++++++++++++++++++++++++++++++switch+(reader.NodeType)
++++++++++++++++++++++++++++++++++++++++{
++++++++++++++++++++++++++++++++++++++++++++case+XmlNodeType.Element:
++++++++++++++++++++++++++++++++++++++++++++++++if+(reader.Name+==+"Field")+//+for+example+i+need+to+read+node+field
++++++++++++++++++++++++++++++++++++++++++++++++{

++++++++++++++++++++++++++++++++++++++++++++++++++++XmlReader+inner+=+reader.ReadSubtree();++//+the+reader+stays+in+the+same++position
++++++++++++++++++++++++++++++++++++++++++++++++++++XElement+El+=+XElement.Load(inner)+as+XElement;
++++++++++++++++++++++++++++++++++++++++++++++++++++inner.Close();
++++++++++++++++++++++++++++++++++++++++++++++++}
++++++++++++++++++++++++++++++++++++++++}
++++++++++++++++++++++++++++++++++++}
++++++++++++++++++++++++++++++++}|code-block|syntax|javascript|2455261|entityMap^0|0|0^^$0|@$1|2|3|4|5|6|7|I|8|@]|9|@]|A|$]]|$1|B|3|C|5|D|7|J|8|@]|9|@]|A|$E|F]]|$1|G|3|-4|5|6|7|K|8|@]|9|@]|A|$]]]|H|$]]

Something like that with ReadSubtree

<pre><code>using (XmlReader reader = XmlReader.Create(new StringReader(xml)))
 {
 reader.MoveToContent();
 while (reader.Read())
 {
 switch (reader.NodeType)
 {
 case XmlNodeType.Element:
 if (reader.Name == "Field") // for example i need to read node field
 {

 XmlReader inner = reader.ReadSubtree(); // the reader stays in the same position
 XElement El = XElement.Load(inner) as XElement;
 inner.Close();
 }
 }
 }
 }
</code></pre>

I got this scenario:

<pre><code>while (reader.Read())
{
 if (reader.NodeType == XmlNodeType.Element &amp;&amp; reader.Name == itemElementName)
 {
 XElement item = null;
 try
 {
 item = XElement.ReadFrom(reader) as XElement;
 }
 catch (XmlException ex)
 {
 //log line number and stuff from XmlException class 
 }
 }
}
</code></pre>

In the above loop I'm transforming a certain node (itemElementName) into an XElement.

Some nodes will be good XML and will go into an XElement, however, some will not.

In the CATCH, I'd like to not only catch the standard XmlException stuff... I'd also like to catch an extract of the current Xml and a string.

However, if I do any kind of READ operation on the node before I pass it to the XElement, it moves the reader forward.

How can get a "snapshot" of the contents of the OuterXml of the reader without interfering with it's position?

How to read from an XmlReader without moving it forwards?

翻译质量差，导致语言生硬或混乱。

没有提供实际的解决方法或示例。

解答不清晰，无法理解或解决问题。

页面排版不美观，阅读体验差。

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我有这样的设想：while (reader.Read()){    if (reader.NodeType == XmlNodeType.Element && reader.Name == itemElementName)    {        XElement item = null;        try    ...

问如何在不向前移动的情况下从XmlReader读取？
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问如何在不向前移动的情况下从XmlReader读取？EN