C# 如何使用 XmlReader 从 XML 中的特定子元素获取值？
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How to get value from a specific child element in XML using XmlReader?
提问by woodykiddy
Here's the XML string.
这是 XML 字符串。
<?xml version="1.0" encoding="utf-16"?>
<questionresponses>
<question id="dd7e3bce-57ee-497a-afe8-e3d8d25e2671">
<text>Question 1?</text>
<response>abcdefg</response>
<correctresponse>123</correctresponse>
</question>
<question id="efc43b1d-048f-4ba9-9cc0-1cc09a7eeaf2">
<text>Question 2?</text>
<response>12345678</response>
<correctresponse>123</correctresponse>
</question>
</questionresponses>
So how could I get value of <response>element by given question Id? Say, if I give id value = "dd7e3bce-57ee-497a-afe8-e3d8d25e2671", I'd like to have string value abcdefgreturned as result.
那么如何<response>通过给定的问题 ID获得元素的值呢？说，如果我给 id value = "dd7e3bce-57ee-497a-afe8-e3d8d25e2671"，我希望字符串值abcdefg作为结果返回。
var xmlstr = "content from above xml example";
using (var reader = XmlReader.Create(new StringReader(xmlstr)))
{
while(reader.Read())
{
if(reader.IsStartElement())
{
var attr = reader["id"];
if(attr != null && attr == "dd7e3bce-57ee-497a-afe8-e3d8d25e2671")
{
if(reader.ReadToDescendant("response"))
{
result = reader.Value; // <= getting empty string? So what's wrong?
break;
}
}
}
}
}
采纳答案by Pranay Rana
you might need to do like this , problem i think is reader is not moving to text and because of that you are getting empty
你可能需要这样做，我认为问题是读者没有转向文本，因此你变得空虚
if(reader.ReadToDescendant("response"))
{
reader.Read();//this moves reader to next node which is text
result = reader.Value; //this might give value than
break;
}
Above one is working for me you can try out at your end
以上一个对我有用，你可以在最后尝试
回答by Anirudha
I would use LINQ2XML..
我会使用 LINQ2XML ..
XDocument doc=XDocument.Parse(xmlstr);
String response=doc.Elements("question")
.Where(x=>x.Attribute("id")==id)
.Single()
.Element("response")
.Value;
回答by Rezoan
You can use this function to get a response for specific questions from XML stored in QuestionXML.xml.
您可以使用此函数从QuestionXML.xml 中存储的 XML 获取对特定问题的响应。
private string getResponse(string questionID)
{
string response = string.Empty;
using (StreamReader sr = new StreamReader("QuestionXML.xml", true))
{
XmlDocument xmlDoc1 = new XmlDocument();
xmlDoc1.Load(sr);
XmlNodeList itemNodes = xmlDoc1.GetElementsByTagName("question");
if (itemNodes.Count > 0)
{
foreach (XmlElement node in itemNodes)
{
if (node.Attributes["id"].Value.ToString() == questionID.Trim())
{
response = node.SelectSingleNode("response").InnerText;
break;
}
}
}
}
return response;
}
回答by gustavo ortega
if (reader.NodeType == XmlNodeType.Element)
{
if(reader.Name == "response")
{
reader.read();
var res = reader.Value;
}
}
//it works for me !!!!
//这个对我有用 ！！！！
