SiteMapProvider.GetParentNode(SiteMapNode) 方法
重要
一些信息与预发行产品相关,相应产品在发行之前可能会进行重大修改。 对于此处提供的信息,Microsoft 不作任何明示或暗示的担保。
当在派生类中被重写时,将检索特定 SiteMapNode 对象的父节点。
public:
abstract System::Web::SiteMapNode ^ GetParentNode(System::Web::SiteMapNode ^ node);
public abstract System.Web.SiteMapNode GetParentNode (System.Web.SiteMapNode node);
abstract member GetParentNode : System.Web.SiteMapNode -> System.Web.SiteMapNode
Public MustOverride Function GetParentNode (node As SiteMapNode) As SiteMapNode
- node
- SiteMapNode
要为其检索父节点的 SiteMapNode。
表示 node
的父节点的 SiteMapNode;如果 SiteMapNode 没有父节点或启用了安全修整且当前用户不能访问父节点,则为 null
。
注意: GetParentNode(SiteMapNode) 如果父节点属于其他提供程序,则也可能返回 null
。 在这种情况下,应改用 node
的 ParentNode 属性。
下面的代码示例演示如何在实现抽象SiteMapProvider类的类中实现GetParentNode方法。 在SimpleTextSiteMapProvider
接口(IList如ArrayList对象)中SiteMapNode存储对象的分层父/子关系。
此代码示例是为类提供的大型示例的 SiteMapProvider 一部分。
// Implement the GetChildNodes method.
public override SiteMapNodeCollection GetChildNodes(SiteMapNode node)
{
SiteMapNodeCollection children = new SiteMapNodeCollection();
// Iterate through the ArrayList and find all nodes that have the specified node as a parent.
lock (this)
{
for (int i = 0; i < childParentRelationship.Count; i++)
{
string nodeUrl = ((DictionaryEntry)childParentRelationship[i]).Key as string;
SiteMapNode parent = GetNode(childParentRelationship, nodeUrl);
if (parent != null && node.Url == parent.Url)
{
// The SiteMapNode with the Url that corresponds to nodeUrl
// is a child of the specified node. Get the SiteMapNode for
// the nodeUrl.
SiteMapNode child = FindSiteMapNode(nodeUrl);
if (child != null)
{
children.Add(child as SiteMapNode);
}
else
{
throw new Exception("ArrayLists not in sync.");
}
}
}
}
return children;
}
protected override SiteMapNode GetRootNodeCore()
{
return RootNode;
}
// Implement the GetParentNode method.
public override SiteMapNode GetParentNode(SiteMapNode node)
{
// Check the childParentRelationship table and find the parent of the current node.
// If there is no parent, the current node is the RootNode.
SiteMapNode parent = null;
lock (this)
{
// Get the Value of the node in childParentRelationship
parent = GetNode(childParentRelationship, node.Url);
}
return parent;
}
' 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))
Else
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