Export (0) Print
Expand All

XContainer.AddFirst Method (Object)

Adds the specified content as the first children of this document or element.

Namespace:  System.Xml.Linq
Assembly:  System.Xml.Linq (in System.Xml.Linq.dll)

'Declaration
Public Sub AddFirst ( _
	content As Object _
)

Parameters

content
Type: System.Object

A content object containing simple content or a collection of content objects to be added.

This method adds the new content before the existing content of the XContainer.

For details about the valid content that can be passed to this function, see Valid Content of XElement and XDocument Objects.

This method will raise the Changed and the Changing events.

The following example creates two XML trees, uses this method to add an XElement object as the first element to one of them. It also adds the results of a LINQ query to the XML tree.

Dim srcTree As XElement = _ 
        <Root>
            <Element1>1</Element1>
            <Element2>2</Element2>
            <Element3>3</Element3>
            <Element4>4</Element4>
            <Element5>5</Element5>
        </Root>

Dim xmlTree As XElement = _ 
        <Root>
            <Child1>1</Child1>
            <Child2>2</Child2>
            <Child3>3</Child3>
            <Child4>4</Child4>
            <Child5>5</Child5>
        </Root>

xmlTree.AddFirst(New XElement("NewChild", "new content"))
xmlTree.AddFirst( _
    From el In srcTree.Elements() _
    Where CInt(el) > 3 _
    Select el _
)
' Even though Child9 does not exist in srcTree, the following statement will not
' throw an exception, and nothing will be added to xmlTree
xmlTree.AddFirst(srcTree.<Child9>)
Console.WriteLine(xmlTree)

This example produces the following output:

<Root>
  <Element4>4</Element4>
  <Element5>5</Element5>
  <NewChild>new content</NewChild>
  <Child1>1</Child1>
  <Child2>2</Child2>
  <Child3>3</Child3>
  <Child4>4</Child4>
  <Child5>5</Child5>
</Root>

.NET Framework

Supported in: 4.5.2, 4.5.1, 4.5, 4, 3.5

.NET Framework Client Profile

Supported in: 4, 3.5 SP1

Portable Class Library

Supported in: Portable Class Library

.NET for Windows Store apps

Supported in: Windows 8

.NET for Windows Phone apps

Supported in: Windows Phone 8.1, Windows Phone 8, Silverlight 8.1

Windows Phone 8.1, Windows Phone 8, Windows 8.1, Windows Server 2012 R2, Windows 8, Windows Server 2012, Windows 7, Windows Vista SP2, Windows Server 2008 (Server Core Role not supported), Windows Server 2008 R2 (Server Core Role supported with SP1 or later; Itanium not supported)

The .NET Framework does not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Show:
© 2014 Microsoft