XmlDocument.GetElementById Method (String)
Gets the XmlElement with the specified ID.
Assembly: System.Xml (in System.Xml.dll)
Parameters
- elementId
-
Type:
System.String
The attribute ID to match.
Return Value
Type: System.Xml.XmlElementThe XmlElement with the matching ID or null if no matching element is found.
If the document has multiple elements with the matching ID, this method returns the first matching element in the document.
Note |
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The DOM implementation must have information which defines which attributes are of type ID. Although attributes of type ID can be defined in either XSD schemas or DTDs, this version of the product only supports those defined in DTDs. Attributes with the name "ID" are not of type ID unless so defined in the DTD. Implementations where it is unknown whether the attributes are of type ID are expected to return null. |
The following example uses the GetElementById method.
Option Explicit Option Strict Imports System Imports System.Xml Public Class Sample Public Shared Sub Main() Dim doc As New XmlDocument() doc.Load("ids.xml") 'Get the first element with an attribute of type ID and value of A111. 'This displays the node <Person SSN="A111" Name="Fred"/>. Dim elem As XmlElement = doc.GetElementById("A111") Console.WriteLine(elem.OuterXml) 'Get the first element with an attribute of type ID and value of A222. 'This displays the node <Person SSN="A222" Name="Tom"/>. elem = doc.GetElementById("A222") Console.WriteLine(elem.OuterXml) End Sub 'Main End Class 'Sample
The example uses the file, ids.xml, as input.
<!DOCTYPE root [ <!ELEMENT root ANY> <!ELEMENT Person ANY> <!ELEMENT Customer EMPTY> <!ELEMENT Team EMPTY> <!ATTLIST Person SSN ID #REQUIRED> <!ATTLIST Customer id IDREF #REQUIRED > <!ATTLIST Team members IDREFS #REQUIRED>]> <root> <Person SSN='A111' Name='Fred'/> <Person SSN='A222' Name='Tom'/> <Customer id='A222334444'/> <Team members='A222334444 A333445555'/> </root>
Available since 1.1
