SiteMapProvider.GetParentNode メソッドとは何？わかりやすく解説 Weblio辞書

.NET Framework クラスライブラリリファレンス

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SiteMapProvider.GetParentNode メソッド

メモ : このメソッドは、.NET Framework version 2.0 で新しく追加されたものです。

派生クラスでオーバーライドされた場合は、特定の SiteMapNode オブジェクトの親ノードを取得します。

名前空間: System.Web
アセンブリ: System.Web (system.web.dll 内)
構文

Visual Basic (宣言)

Public MustOverride Function
 GetParentNode ( _
    node As SiteMapNode _
) As SiteMapNode

Visual Basic (使用法)

Dim instance As SiteMapProvider
Dim node As SiteMapNode
Dim returnValue As SiteMapNode

returnValue = instance.GetParentNode(node)

public abstract SiteMapNode GetParentNode (
    SiteMapNode node
)

C++

public:
virtual SiteMapNode^ GetParentNode (
    SiteMapNode^ node
) abstract

public abstract SiteMapNode GetParentNode (
    SiteMapNode node
)

JScript

public abstract function GetParentNode (
    node : SiteMapNode
) : SiteMapNode

パラメータ

node: 親ノードを取得する対象の SiteMapNode。

戻り値
node の親を表す SiteMapNode。SiteMapNode に親がない場合、またはセキュリティトリミングが有効で、現在のユーザーが親ノードにアクセスできない場合は、null 参照 (Visual Basic では Nothing)。

使用例

SiteMapProvider 抽象クラスを実装するクラスに GetParentNode メソッドを実装する方法を次のコード例に示します。SimpleTextSiteMapProvider は、SiteMapNode オブジェクト間の親子関係の階層を、ArrayList オブジェクトなどの IList インターフェイスに格納します。

このコード例は、SiteMapProvider クラスのトピックで取り上げているコード例の一部分です。

Visual Basic

' 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

// 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;
}