Linq and updating data RSS

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  Gabrielle

  Member

  106 Points

  146 Posts

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  Linq and updating data

  Jun 10, 2008 11:25 PM | LINK

  Here is the code:

  public void SaveContentFromPage(string controlName, string Text)

  {

  XDocument doc = XDocument.Load(@"C:/PageContentData.xml");

  foreach (var c in doc.Descendants("DataItem").Elements("Name"))

  if ((string)c.Element("Name") == controlName)doc.Element("DataItem").Element("Content").ReplaceNodes(Text);

  }

   

  VS says at last line that Object reference not set to an instance of an object.

  What am I doing wrong?

   My XML file is:

  <?xml version="1.0" encoding="utf-8" ?>

  <ContentData>

  <DataItem>

  <Name>Header</Name>

  <Content>HELLO JULI! HOW ARE YOU TODAY?</Content>

  </DataItem>

  <DataItem>

  <Name>Header2</Name>

  <Content>HELLO JULIsdfsdfdsfsdf! HOW ARE YOU TODAY?</Content>

  </DataItem>

  <DataItem>

  <Name>Header343</Name>

  <Content>HELLO dfdsJULI! HOW ARE YOU TODAY?</Content>

  </DataItem>

  </ContentData>

• 

  Leonid Andruhin

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  Re: Linq and updating data

  Jun 11, 2008 06:39 AM | LINK

  string s = "<?xml version=\"1.0\" encoding=\"utf-8\" ?> <ContentData><DataItem> <Name>Header</Name><Content>HELLO JULI! HOW ARE YOU TODAY?</Content> </DataItem><DataItem> <Name>Header2</Name><Content>HELLO JULIsdfsdfdsfsdf! HOW ARE YOU TODAY?</Content> </DataItem><DataItem> <Name>Header343</Name><Content>HELLO dfdsJULI! HOW ARE YOU TODAY?</Content> </DataItem></ContentData>";

  System.Xml.Linq.XDocument doc = System.Xml.Linq.XDocument.Parse(s);

  foreach (var c in doc.Descendants("DataItem"))

  if ((string)c.Element("Name") == controlName)

  c.Element("Content").ReplaceNodes(Text);

  System.Text.StringBuilder sb = new System.Text.StringBuilder();

  System.IO.StringWriter sr = new System.IO.StringWriter(sb);

  doc.Save(sr);

  string ss = sb.ToString();//result

  sr.Close();

• 

  Yi-Lun Luo -...

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  Microsoft

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  Re: Linq and updating data

  Jun 12, 2008 05:51 AM | LINK

  Hello, you're trying to load a file from the user's local system. For security reasons, this is not allowed. You can, however, open and save a file without user interaction from the isolated storage, or open a file (but not save it) with OpenFileDialog as the user requests, or download and upload a file from the web. Either way, Leonid has shown you how to update the xml content. After that, to save the string to a file in isolated storage, please refer to that quick start. To upload the string to web, you can use WebClient.UploadString, use an HttpWebRequest to do a POST, or call a web service method. On the server side, you save the string to a file.

  shanaolanxing - I'll transfer to the Windows Azure team, and will have limited time to participate in the Silverlight forum. Apologize if I don't answer your questions in time.