xmldocument.selectsinglenode always returns null RSS

• • Reply
  

  dotnet16

  Member

  155 Points

  113 Posts

  xmldocument.selectsinglenode always returns null

  Jan 15, 2013 12:46 PM|LINK

  Here is my code:

  XmlDocument doc = new XmlDocument();

  doc.LoadXml("<mail><res><stat><msg><test>testerror</test></msg></stat></resp></mail>");

  string err = doc.SelectSingleNode("res/stat/msg").InnerText;

   

  I need to set my xml so that err is not null.But with the above code it is always null.How should I set my XML?

• • Reply
  

  Rion William...

  All-Star

  27896 Points

  4618 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 15, 2013 01:02 PM|LINK

  You needed your outer <mail> element including within your SelectSingleNode() method : 

  XmlDocument doc = new XmlDocument();
  doc.LoadXml("<mail><res><stat><msg><test>testerror</test></msg></stat></res></mail>");
  string err = doc.SelectSingleNode("mail/res/stat/msg").InnerText;

  Additionally, you had a misspelling in your second <res> tag (it was previously <resp>).

  Blog | Twitter | Stack Overflow | LinkedIn
  • Edited by Rion Williams on Jan 15, 2013 01:03 PM
  • Edited by Rion Williams on Jan 15, 2013 01:03 PM
• • Reply
  

  dotnet16

  Member

  155 Points

  113 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 16, 2013 03:53 AM|LINK

  Rion,

  Thanks for your reply.My need is such that the 'doc.SelectSingleNode("mail/res/stat/msg").InnerText;' shouldn't change.

  I can vary my doc but the 'err' should never be null.

  So I can't use the string err = doc.SelectSingleNode("mail/res/stat/msg").InnerText; as you suggested.

• • Reply
  

  Rion William...

  All-Star

  27896 Points

  4618 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 16, 2013 04:14 AM|LINK

  So you basically want to store the "deepest" element given a single XML string? If that is the case - you could use the following XPath expression : 

  string yourDeepestText = doc.SelectSingleNode("/*[descendant::*]").InnerText;

  Examples:

  //Three XML Documents
  XmlDocument doc = new XmlDocument();
  doc.LoadXml("<mail><res><stat><msg><test>error</test></msg></stat></res></mail>");
  XmlDocument doc2 = new XmlDocument();
  doc2.LoadXml("<asp><dot><net><rules>testing</rules></net></dot></asp>");
  XmlDocument doc3 = new XmlDocument();
  doc3.LoadXml("<this><is><a><test><now>ASP</now></test></a></is></this>");
  
  //Each processed through the same expression
  string d1 = doc.SelectSingleNode("/*[descendant::*]").InnerText; //d1 = "error"
  string d2 = doc2.SelectSingleNode("/*[descendant::*]").InnerText; //d2 = "testing"
  string d3 = doc3.SelectSingleNode("/*[descendant::*]").InnerText; //d3 = "ASP"

  
  
  

  Blog | Twitter | Stack Overflow | LinkedIn
  • Edited by Rion Williams on Jan 16, 2013 04:17 AM
  • Edited by Rion Williams on Jan 16, 2013 04:31 AM
  • Edited by Rion Williams on Jan 16, 2013 04:32 AM
• • Reply
  

  dotnet16

  Member

  155 Points

  113 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 16, 2013 04:50 AM|LINK

  Rion,

  My code for 'doc.SelectSingleNode' need not be changed.i.e., I have to change my doc so that

  doc.SelectSingleNode("res/stat/msg") is not null.

  Can you pls suggest me a way of setting the doc accordingly.

   

   

• • Reply
  

  Rion William...

  All-Star

  27896 Points

  4618 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 16, 2013 05:04 AM|LINK

  Using the original answer that I had suggested : 

  XmlDocument doc = new XmlDocument();
  doc.LoadXml("<mail><res><stat><msg><test></test></msg></stat></res></mail>");
  string err = doc.SelectSingleNode("mail/res/stat/msg").InnerText;

  and revising it to handle null checking - you can use : 

  //Checks for any nulls - if none are found it will output properly, otherwise it will output ""
  string err = (doc.SelectSingleNode("mail/res/stat/msg") != null) ? doc.SelectSingleNode("mail/res/stat/msg").InnerText : "";

  Revised Answer

  XmlDocument doc = new XmlDocument();
  doc.LoadXml("<mail><res><stat><msg><test></test></msg></stat></res></mail>");
  string err = (doc.SelectSingleNode("mail/res/stat/msg") != null) ? doc.SelectSingleNode("mail/res/stat/msg").InnerText : "";

  
  
  
  

  Blog | Twitter | Stack Overflow | LinkedIn
  • Edited by Rion Williams on Jan 16, 2013 05:04 AM
• • Reply
  

  dotnet16

  Member

  155 Points

  113 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 16, 2013 08:02 AM|LINK

  Since I can't change the doc.SelectSingleNode statement,I used the following code:

  XmlDocument doc = new XmlDocument(); 
  doc.LoadXml("res><stat><msg><test></test></msg></stat></res>");
  string err = doc.SelectSingleNode("res/stat/msg").InnerText;

  This works.

  • Edited by dotnet16 on Jan 16, 2013 08:03 AM
  • Marked as answer by decker dong - msft on Jan 21, 2013 12:40 AM
• • Reply
  

  Decker Dong ...

  All-Star

  118619 Points

  18779 Posts

  Re: xmldocument.selectsinglenode always returns null

  Jan 17, 2013 12:23 AM|LINK

  dotnet16

  Since I can't change the doc.SelectSingleNode statement,I used the following code:
  XmlDocument doc =
  new XmlDocument();
  
  doc.LoadXml("res><stat><msg><test></test></msg></stat></res>");
  
  string err = doc.SelectSingleNode("res/stat/msg").InnerText;
  This works.

  Hi,

  Since your problem is solved. I'll mark it as an answer to close this thread.

  Anything feedback, please feel free to continue by creating another new thread.

  Reguards!