我需要读取xml文件中的所有嵌套元素。以下是该计划。在下面的程序中，我能够获得问题和答案的值，但不能获得SubQuestionAnswer / Question和SubQuestionAnswer / Answer。有人能告诉我程序中有什么问题
XmlDocument xmlDocument = new XmlDocument();
var fataQuestionnaire = @"<?xml version=""1.0"" encoding=""UTF-16""?>
<FatcaQuestionnaire xmlns:xsi=""http://www.w3.org/2001/XMLSchema-instance"" xmlns:xsd=""http://www.w3.org/2001/XMLSchema"">
<QuestionAnswers>
<QuestionAnswer>
<Question>What is your source of wealth?</Question>
<Answer>I am italian </Answer>
</QuestionAnswer>
<QuestionAnswer>
<Question>What is your occupation and name of employer?</Question>
<Answer>Bestinvest</Answer>
</QuestionAnswer>
<QuestionAnswer>
<Question>Do you have a business or residence in?</Question>
<Answer>Yes</Answer>
</QuestionAnswer>
<QuestionAnswer>
<Question>How long have you lived outside of Albania</Question>
<Answer>5 years</Answer>
</QuestionAnswer>
<QuestionAnswer>
<Question>Do you return to Albania on a regular basis</Question>
<Answer>Yes</Answer>
<SubQuestionAnswer>
<Question>How frequently?</Question>
<Answer>every year</Answer>
</SubQuestionAnswer>
</QuestionAnswer>
<QuestionAnswer>
<Question>Do you have family in Albania?</Question>
<Answer>Yes</Answer>
<SubQuestionAnswer>
<Question>Family relationship?</Question>
<Answer>My parents lives there</Answer>
</SubQuestionAnswer>
</QuestionAnswer>
<QuestionAnswer>
<Question>Are you connected to the government of Albania?</Question>
<Answer>Yes</Answer>
<SubQuestionAnswer>
<Question>Nature of association</Question>
<Answer>I was an ex minister</Answer>
</SubQuestionAnswer>
</QuestionAnswer>
<QuestionAnswer>
<Question>Do you send or receive money from Albania?</Question>
<Answer>Yes</Answer>
<SubQuestionAnswer>
<Question>How often and why?</Question>
<Answer>Every month for my parents to live with.</Answer>
</SubQuestionAnswer>
</QuestionAnswer>
</QuestionAnswers>
</FatcaQuestionnaire>";
XmlTextReader reader = new XmlTextReader(new StringReader(fataQuestionnaire));
xmlDocument.Load(reader);
XmlElement xmlRoot = xmlDocument.DocumentElement;
if (xmlRoot != null)
{
XmlNodeList xnlNodes = xmlRoot.SelectNodes("/FatcaQuestionnaire/QuestionAnswers/QuestionAnswer");
string questionanswer =string.Empty;
if (xnlNodes != null)
foreach (XmlNode xndNode in xnlNodes)
{
if (xndNode["Question"] != null)
questionanswer = (xndNode["Question"].InnerText);
if (xndNode["Answer"] != null)
questionanswer = (xndNode["Answer"].InnerText);
if (xndNode["SubQuestionAnswer/Question"] != null)
questionanswer = (xndNode["SubQuestionAnswer/Question"].InnerText);
if (xndNode["SubQuestionAnswer/Answer"] != null)
questionanswer = (xndNode["SubQuestionAnswer/Answer"].InnerText);
}
}
答案 0 :(得分：1)
索引器不支持XPath语法。你可以这样修理它：
if (xndNode["SubQuestionAnswer"] != null)
{
if (xndNode["SubQuestionAnswer"]["Question"] != null)
questionanswer = (xndNode["SubQuestionAnswer"]["Question"].InnerText);
if (xndNode["SubQuestionAnswer"]["Answer"] != null)
questionanswer = (xndNode["SubQuestionAnswer"]["Answer"].InnerText);
}
答案 1 :(得分：1)
另一种选择：使用XDocument和Linq。而不是XmlDocument。
加载xml：
XDocument doc = XDocument.Parse(fataQuestionnaire);
使用示例：
List<KeyValuePair<string,string>> allQuestionAnswers = doc.Descendants("QuestionAnswer").Union(doc.Descendants("SubQuestionAnswer"))
.Select(qa=>new KeyValuePair<string,string>(qa.Element("Question").Value, qa.Element("Answer").Value)).ToList();
foreach (var pair in allQuestionAnswers)
{
Console.WriteLine("Q: " + pair.Key +"\nA: " + pair.Value + "\n");
}
结果：
Q: What is your occupation and name of employer?
A: Bestinvest
Q: Do you have a business or residence in?
A: Yes
Q: How long have you lived outside of Albania
A: 5 years
Q: Do you return to Albania on a regular basis
A: Yes
Q: Do you have family in Albania?
A: Yes
Q: Are you connected to the government of Albania?
A: Yes
Q: Do you send or receive money from Albania?
A: Yes
Q: How frequently?
A: every year
Q: Family relationship?
A: My parents lives there
Q: Nature of association
A: I was an ex minister
Q: How often and why?
A: Every month for my parents to live with.
或：
doc.Descendants("QuestionAnswer").ToList().ForEach(qa =>
{
Console.WriteLine("Q: " + qa.Element("Question").Value + "\nA: " + qa.Element("Answer").Value);
var sqa = qa.Element("SubQuestionAnswer");
if (sqa != null)
{
Console.WriteLine("\tQ: " + sqa.Element("Question").Value + "\n\tA: " + sqa.Element("Answer").Value);
}
Console.WriteLine();
});
结果：
Q: What is your source of wealth?
A: I am italian
Q: What is your occupation and name of employer?
A: Bestinvest
Q: Do you have a business or residence in?
A: Yes
Q: How long have you lived outside of Albania
A: 5 years
Q: Do you return to Albania on a regular basis
A: Yes
Q: How frequently?
A: every year
Q: Do you have family in Albania?
A: Yes
Q: Family relationship?
A: My parents lives there
Q: Are you connected to the government of Albania?
A: Yes
Q: Nature of association
A: I was an ex minister
Q: Do you send or receive money from Albania?
A: Yes
Q: How often and why?
A: Every month for my parents to live with.