SiteMapNodeCollection.Add Method (SiteMapNode)


Adds a single SiteMapNode object to the collection.

Namespace:   System.Web
Assembly:  System.Web (in System.Web.dll)

Public Overridable Function Add (
	value As SiteMapNode
) As Integer


Type: System.Web.SiteMapNode

The SiteMapNode to add to the SiteMapNodeCollection.

Return Value

Type: System.Int32

The index of the InnerList where the SiteMapNode was inserted.

Exception Condition

value is null.


The SiteMapNodeCollection is read-only.

You cannot add a SiteMapNode object to a read-only or fixed-size SiteMapNodeCollection collection. You can test whether a SiteMapNodeCollection is read-only by checking the IsReadOnly property.

This section contains two code examples. The first code example demonstrates how to create a new SiteMapNodeCollection collection and add elements to it. The second code example demonstrates how to add elements to a custom site map provider.

The following code example demonstrates how to use the SiteMapNodeCollection constructor to create a new SiteMapNodeCollection, and then add elements to it with the Add method.

' The LoadSiteMapData() Function loads site navigation
' data from persistent storage into a DataTable.

Dim siteMapData As DataTable
siteMapData = LoadSiteMapData()

' Create a SiteMapNodeCollection.
Dim nodes As New SiteMapNodeCollection()

' Create a SiteMapNode and add it to the collection.
Dim tempNode As SiteMapNode
Dim row As DataRow
Dim index As Integer
index = 0

While (index < siteMapData.Rows.Count)

    row = siteMapData.Rows(index)

    ' Create a node based on the data in the DataRow.
    tempNode = New SiteMapNode(SiteMap.Provider, row("Key").ToString(), row("Url").ToString())

    ' Add the node to the collection.
    index = index + 1
End While

The following code example demonstrates a custom site map provider implementation and shows how to use the SiteMapNodeCollection constructor to create a new SiteMapNodeCollection and add elements to the SiteMapNodeCollection with the Add method.

This code example is part of a larger code example provided for the SiteMapProvider class.

' Implement the GetChildNodes method.
Public Overrides Function GetChildNodes(ByVal node As SiteMapNode) As SiteMapNodeCollection
  Dim children As New SiteMapNodeCollection()
  ' Iterate through the ArrayList and find all nodes that have the specified node as a parent.
  SyncLock Me
    Dim i As Integer
    For i = 0 To childParentRelationship.Count - 1

      Dim de As DictionaryEntry = CType(childParentRelationship(i), DictionaryEntry)
      Dim nodeUrl As String = CType(de.Key, String)

      Dim parent As SiteMapNode = GetNode(childParentRelationship, nodeUrl)

      If Not (parent Is Nothing) AndAlso node.Url = parent.Url Then
        ' The SiteMapNode with the Url that corresponds to nodeUrl
        ' is a child of the specified node. Get the SiteMapNode for
        ' the nodeUrl.
        Dim child As SiteMapNode = FindSiteMapNode(nodeUrl)
        If Not (child Is Nothing) Then
          children.Add(CType(child, SiteMapNode))
          Throw New Exception("ArrayLists not in sync.")
        End If
      End If
    Next i
  End SyncLock
  Return children
End Function 'GetChildNodes

Protected Overrides Function GetRootNodeCore() As SiteMapNode
  Return RootNode
End Function ' GetRootNodeCore()

' Implement the GetParentNode method.
Public Overrides Function GetParentNode(ByVal node As SiteMapNode) As SiteMapNode
  ' Check the childParentRelationship table and find the parent of the current node.
  ' If there is no parent, the current node is the RootNode.
  Dim parent As SiteMapNode = Nothing
  SyncLock Me
    ' Get the Value of the node in childParentRelationship
    parent = GetNode(childParentRelationship, node.Url)
  End SyncLock
  Return parent
End Function 'GetParentNode

.NET Framework
Available since 2.0
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