Compartilhar via


StaticSiteMapProvider.BuildSiteMap Método

Definição

Quando substituído em uma classe derivada, carrega as informações do mapa do site do armazenamento persistente e o compila na memória.

public:
 abstract System::Web::SiteMapNode ^ BuildSiteMap();
public abstract System.Web.SiteMapNode BuildSiteMap ();
abstract member BuildSiteMap : unit -> System.Web.SiteMapNode
Public MustOverride Function BuildSiteMap () As SiteMapNode

Retornos

SiteMapNode

O SiteMapNode raiz da estrutura de navegação do mapa do site.

Exemplos

O exemplo de código a seguir demonstra como implementar o BuildSiteMap método para recuperar dados de um banco de dados do Microsoft Access e objetos de build SiteMapNode que são adicionados à ChildNodes coleção do nó de mapa do site raiz. Por fim, a RootNode propriedade é retornada ao chamador.

Este exemplo de código faz parte de um exemplo maior fornecido para a StaticSiteMapProvider classe.

// Build an in-memory representation from persistent
// storage, and return the root node of the site map.
virtual SiteMapNode ^ BuildSiteMap() override
{
   // Since the SiteMap class is static, make sure that it is
   // not modified while the site map is built.
   System::Threading::Monitor::Enter( this );
   try
   {
      
      // If there is no initialization, this method is being
      // called out of order.
      if (  !IsInitialized )
      {
         throw gcnew Exception( "BuildSiteMap called incorrectly." );
      }
      
      // If there is no root node, then there is no site map.
      if ( nullptr == rootNode )
      {
         
         // Start with a clean slate
         Clear();
         
         // Select the root node of the site map from Microsoft Access.
         int rootNodeId = -1;
         if ( accessConnection->State == ConnectionState::Closed )
            accessConnection->Open();
         
         OleDbCommand^ rootNodeCommand = gcnew OleDbCommand
            ("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid IS NULL", accessConnection);
         OleDbDataReader^ rootNodeReader = rootNodeCommand->ExecuteReader();
         if ( rootNodeReader->HasRows )
         {
            rootNodeReader->Read();
            rootNodeId = rootNodeReader->GetInt32( 0 );
            
            // Create a SiteMapNode that references the current StaticSiteMapProvider.
            rootNode = gcnew SiteMapNode(this, rootNodeId.ToString(), 
               rootNodeReader->GetString( 1 ),rootNodeReader->GetString( 2 ));
         }
         else
            return nullptr;
         rootNodeReader->Close();
         
         // Select the child nodes of the root node.
         OleDbCommand^ childNodesCommand = gcnew OleDbCommand
            ("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid = ?", accessConnection);
         OleDbParameter^ rootParam = gcnew OleDbParameter( "parentid", OleDbType::Integer);
         rootParam->Value = rootNodeId;
         childNodesCommand->Parameters->Add( rootParam );
         OleDbDataReader^ childNodesReader = childNodesCommand->ExecuteReader();
         if ( childNodesReader->HasRows )
         {
            SiteMapNode ^ childNode = nullptr;
            while ( childNodesReader->Read() )
            {
               childNode = gcnew SiteMapNode( this, 
                   System::Convert::ToString(childNodesReader->GetInt32( 0 )),
                  childNodesReader->GetString( 1 ),
                  childNodesReader->GetString( 2 ) 
               );
               // Use the SiteMapNode AddNode method to add
               // the SiteMapNode to the ChildNodes collection.
               AddNode( childNode, rootNode );
            }
         }
         childNodesReader->Close();
         accessConnection->Close();
      }
      return rootNode;
   }
   finally
   {
      System::Threading::Monitor::Exit( this );
   }

}
// Build an in-memory representation from persistent
// storage, and return the root node of the site map.
public override SiteMapNode BuildSiteMap() {

    // Since the SiteMap class is static, make sure that it is
    // not modified while the site map is built.
    lock(this) {

        // If there is no initialization, this method is being
        // called out of order.
        if (! IsInitialized) {
            throw new Exception("BuildSiteMap called incorrectly.");
        }

        // If there is no root node, then there is no site map.
        if (null == rootNode) {
            // Start with a clean slate
            Clear();

            // Select the root node of the site map from Microsoft Access.
            int rootNodeId = -1;

            if (accessConnection.State == ConnectionState.Closed)
                accessConnection.Open();
            OleDbCommand rootNodeCommand =
                new OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid IS NULL",
                                 accessConnection);
            OleDbDataReader rootNodeReader = rootNodeCommand.ExecuteReader();

            if(rootNodeReader.HasRows) {
                rootNodeReader.Read();
                rootNodeId = rootNodeReader.GetInt32(0);
                // Create a SiteMapNode that references the current StaticSiteMapProvider.
                rootNode   = new SiteMapNode(this,
                                             rootNodeId.ToString(),
                                             rootNodeReader.GetString(1),
                                             rootNodeReader.GetString(2));
            }
            else
            {
                return null;
            }

            rootNodeReader.Close();
            // Select the child nodes of the root node.
            OleDbCommand childNodesCommand =
                new OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid = ?",
                                 accessConnection);
            OleDbParameter rootParam = new OleDbParameter("parentid", OleDbType.Integer);
            rootParam.Value = rootNodeId;
            childNodesCommand.Parameters.Add(rootParam);

            OleDbDataReader childNodesReader = childNodesCommand.ExecuteReader();

            if (childNodesReader.HasRows) {

                SiteMapNode childNode = null;
                while(childNodesReader.Read()) {
                    childNode =  new SiteMapNode(this,
                                                 childNodesReader.GetInt32(0).ToString(),
                                                 childNodesReader.GetString(1),
                                                 childNodesReader.GetString(2));

                    // Use the SiteMapNode AddNode method to add
                    // the SiteMapNode to the ChildNodes collection.
                    AddNode(childNode, rootNode);
                }
            }

            childNodesReader.Close();
            accessConnection.Close();
        }
        return rootNode;
    }
}
' Build an in-memory representation from persistent
' storage, and return the root node of the site map.
Public Overrides Function BuildSiteMap() As SiteMapNode

    ' Since the SiteMap class is static, make sure that it is
    ' not modified while the site map is built.
    SyncLock Me

        ' If there is no initialization, this method is being
        ' called out of order.
        If Not IsInitialized Then
            Throw New Exception("BuildSiteMap called incorrectly.")
        End If

        ' If there is no root node, then there is no site map.
        If aRootNode Is Nothing Then
            ' Start with a clean slate
            Clear()

            ' Select the root node of the site map from Microsoft Access.
            Dim rootNodeId As Integer = -1

            If accessConnection.State = ConnectionState.Closed Then
                accessConnection.Open()
            End If
            Dim rootNodeCommand As New OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid IS NULL", accessConnection)
            Dim rootNodeReader As OleDbDataReader = rootNodeCommand.ExecuteReader()

            If rootNodeReader.HasRows Then
                rootNodeReader.Read()
                rootNodeId = rootNodeReader.GetInt32(0)
                ' Create a SiteMapNode that references the current StaticSiteMapProvider.
                aRootNode = New SiteMapNode(Me, rootNodeId.ToString(), rootNodeReader.GetString(1), rootNodeReader.GetString(2))
            Else
                Return Nothing
            End If
            rootNodeReader.Close()
            ' Select the child nodes of the root node.
            Dim childNodesCommand As New OleDbCommand("SELECT nodeid, url, name FROM SiteMap WHERE parentnodeid = ?", accessConnection)
            Dim rootParam As New OleDbParameter("parentid", OleDbType.Integer)
            rootParam.Value = rootNodeId
            childNodesCommand.Parameters.Add(rootParam)

            Dim childNodesReader As OleDbDataReader = childNodesCommand.ExecuteReader()

            If childNodesReader.HasRows Then

                Dim childNode As SiteMapNode = Nothing
                While childNodesReader.Read()
                    childNode = New SiteMapNode(Me, _
                    childNodesReader.GetInt32(0).ToString(), _
                    childNodesReader.GetString(1), _
                    childNodesReader.GetString(2))

                    ' Use the SiteMapNode AddNode method to add
                    ' the SiteMapNode to the ChildNodes collection.
                    AddNode(childNode, aRootNode)
                End While
            End If

            childNodesReader.Close()
            accessConnection.Close()
        End If
        Return aRootNode
    End SyncLock

End Function 'BuildSiteMap

Comentários

O BuildSiteMap método é o único membro abstrato da StaticSiteMapProvider classe. O BuildSiteMap método é chamado para carregar e compilar o nó de mapa do site a partir do armazenamento persistente. Ao implementar o BuildSiteMap método, verifique se ele é thread-safe, pois várias solicitações de página simultâneas podem resultar indiretamente em várias chamadas para carregar informações do mapa do site.

Notas aos Implementadores

Ao substituir o BuildSiteMap() método em uma classe derivada, certifique-se de normalizar as URLs de SiteMapNode objetos que você adiciona ao provedor de mapa de site, para que o FindSiteMapNode(String) método possa recuperar um nó de mapa do site, independentemente de a URL do nó de mapa do site ser fornecida como um caminho virtual absoluto ou um caminho relativo do aplicativo. Os implementadores do provedor de mapa de site usando o AddNode método devem normalizar quaisquer URLs antes de SiteMapNode armazenar objetos nas tabelas de hash internas em nome do provedor de mapa do site.

O comportamento de corte de segurança é incluído nas implementações de classe e StaticSiteMapProvider na SiteMapProvider classe. No entanto, para que o corte de segurança funcione em classes derivadas, você deve definir a propriedade de todos SiteMapNode os Roles objetos criados durante a criação de um provedor de mapa de site ao substituir o BuildSiteMap() método.

Aplica-se a

Confira também