InfoPath Dev

 I'm trying to retrieve the display name (Owner node in the XML below) of an item selected in an InfoPath dropdown list to use to populate in a separate text box. Below is the code I'm attempting to use.

While running the code I'm getting the error "Expression must evaluate to a node-set." Any help would be appreciated, or if there is a better way to get the display name (Owner field).

-----------------------------------

   XPathNavigator _xnDoc = MainDataSource.CreateNavigator();
            XPathNodeIterator iter = _xnDoc.Select("/my:myFields/my:Document/my:Assigned_Entity",
              NamespaceManager);

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

          string value = iter.Current.Value;

          XPathNavigator secDS = DataSources["OwnerEntity"].CreateNavigator();

          string displayName = secDS.SelectSingleNode(
              "/dfs:myFields/dfs:dataFields/dsf:OwnerEntity/[@value = '"
              + value + "']/@owner", NamespaceManager).Value;

            sb.Append(displayName);
            sb.Append(";");

            _xnDoc.SelectSingleNode("//my:myFields/my:Document/my:owner").SetValue(displayName);

 

--------------------------------------------

 The secondary data source (OwnerEntity) returns xml in the below format:

- <options>

- <option>

  <value>Corporate</value>

  <displayname>Corporate</displayname>

  <owner>CNC</owner>

  <uniquenumber>000123456</uniquenumber>

  </option>

- <option>

  <value>UHN</value>

  <displayname>UHN</displayname>

  <owner>Business</owner>

  <uniquenumber>000123457</uniquenumber>

  </option>

- <option>

  <value>Main</value>

  <displayname>Main</displayname>

  <owner>IT</owner>

  <uniquenumber>000123458</uniquenumber>

  </option>

  </options>

 

 

 

Hi, and welcome:

It is your XPath that is the problem, I suspect.

Rather than this: "/dfs:myFields/dfs:dataFields/dsf:OwnerEntity/[@value = '" + value + "']/@owner"

Try this: "/dfs:myFields/dfs:dataFields/dsf:OwnerEntity/@owner[../@value = '" + value + "']"