PrependChild

CompositeNode.PrependChild<T> method

Adds the specified node to the beginning of the list of child nodes for this node.

public T PrependChild<T>(T newChild)
    where T : Node
ParameterTypeDescription
newChildTThe node to add.

Return Value

The node added.

Remarks

If the newChild is already in the tree, it is first removed.

If the node being inserted was created from another document, you should use ImportNode to import the node to the current document. The imported node can then be inserted into the current document.

Examples

Shows how to add, update and delete child nodes in a CompositeNode’s collection of children.

Document doc = new Document();

// An empty document, by default, has one paragraph.
Assert.AreEqual(1, doc.FirstSection.Body.Paragraphs.Count);

// Composite nodes such as our paragraph can contain other composite and inline nodes as children.
Paragraph paragraph = doc.FirstSection.Body.FirstParagraph;
Run paragraphText = new Run(doc, "Initial text. ");
paragraph.AppendChild(paragraphText);

// Create three more run nodes.
Run run1 = new Run(doc, "Run 1. ");
Run run2 = new Run(doc, "Run 2. ");
Run run3 = new Run(doc, "Run 3. ");

// The document body will not display these runs until we insert them into a composite node
// that itself is a part of the document's node tree, as we did with the first run.
// We can determine where the text contents of nodes that we insert
// appears in the document by specifying an insertion location relative to another node in the paragraph.
Assert.AreEqual("Initial text.", paragraph.GetText().Trim());

// Insert the second run into the paragraph in front of the initial run.
paragraph.InsertBefore(run2, paragraphText);

Assert.AreEqual("Run 2. Initial text.", paragraph.GetText().Trim());

// Insert the third run after the initial run.
paragraph.InsertAfter(run3, paragraphText);

Assert.AreEqual("Run 2. Initial text. Run 3.", paragraph.GetText().Trim());

// Insert the first run to the start of the paragraph's child nodes collection.
paragraph.PrependChild(run1);

Assert.AreEqual("Run 1. Run 2. Initial text. Run 3.", paragraph.GetText().Trim());
Assert.AreEqual(4, paragraph.GetChildNodes(NodeType.Any, true).Count);

// We can modify the contents of the run by editing and deleting existing child nodes.
((Run)paragraph.GetChildNodes(NodeType.Run, true)[1]).Text = "Updated run 2. ";
paragraph.GetChildNodes(NodeType.Run, true).Remove(paragraphText);

Assert.AreEqual("Run 1. Updated run 2. Run 3.", paragraph.GetText().Trim());
Assert.AreEqual(3, paragraph.GetChildNodes(NodeType.Any, true).Count);

See Also

CompositeNode.InsertBefore CompositeNode.RemoveAllChildren