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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)

public void AddFirst(
	params Object[] content
)

Parameters

content
Type: System.Object[]
A parameter list of content objects.

ExceptionCondition
InvalidOperationException

The parent is null.

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, and 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.


StringBuilder output = new StringBuilder();
XElement srcTree = new XElement("Root",
    new XElement("Element1", 1),
    new XElement("Element2", 2),
    new XElement("Element3", 3),
    new XElement("Element4", 4),
    new XElement("Element5", 5)
);
XElement xmlTree = new XElement("Root",
    new XElement("Child1", 1),
    new XElement("Child2", 2),
    new XElement("Child3", 3),
    new XElement("Child4", 4),
    new XElement("Child5", 5)
);
xmlTree.AddFirst(new XElement("NewChild", "new content"));
xmlTree.AddFirst(
    from el in srcTree.Elements()
    where (int)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.Element("Child9"));
output.Append(xmlTree  + Environment.NewLine);

OutputTextBlock.Text = output.ToString();


Silverlight

Supported in: 5, 4, 3

Silverlight for Windows Phone

Supported in: Windows Phone OS 7.1, Windows Phone OS 7.0

XNA Framework

Supported in: Xbox 360, Windows Phone OS 7.0

For a list of the operating systems and browsers that are supported by Silverlight, see Supported Operating Systems and Browsers.

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