Exemple

L'exemple de code suivant décrit comment vous pouvez étendre la classe StaticSiteMapProvider pour utiliser Microsoft Access comme fournisseur sitemap. Le fournisseur sitemap utilise le fournisseur de données .NET Framework pour OLE DB pour se connecter à la base de données Access.

Visual Basic

Imports System
Imports System.Collections
Imports System.Collections.Specialized
Imports System.Data
Imports System.Data.OleDb
Imports System.Security.Permissions
Imports System.Web

Namespace Samples.AspNet.VB.Controls
 
    ' An extremely simple AccessSiteMapProvider that only supports a
    ' site map node hierarchy one level deep.
    <AspNetHostingPermission(SecurityAction.Demand, Level:=AspNetHostingPermissionLevel.Minimal)> _
    Public Class AccessSiteMapProvider
        Inherits StaticSiteMapProvider

        Private aRootNode As SiteMapNode = Nothing
        Private accessConnection As OleDbConnection = Nothing

        ' This string is case sensitive.
        Private AccessConnectionStringName As String = "accessSiteMapConnectionString"

        ' Implement a default constructor.
        Public Sub New()
        End Sub 'New

        ' Some basic state to help track the initialization state of the provider.
        Private initialized As Boolean = False

        Public Overridable ReadOnly Property IsInitialized() As Boolean
            Get
                Return initialized
            End Get
        End Property

        ' Return the root node of the current site map.
        Public Overrides ReadOnly Property RootNode() As SiteMapNode
            Get
                Return BuildSiteMap()
            End Get
        End Property

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

        ' Initialize is used to initialize the properties and any state that the
        ' AccessProvider holds, but is not used to build the site map.
        ' The site map is built when the BuildSiteMap method is called.
        Public Overrides Sub Initialize(ByVal name As String, ByVal attributes As NameValueCollection)
            If IsInitialized Then
                Return
            End If
            MyBase.Initialize(name, attributes)

            ' Create and test the connection to the Microsoft Access database.
            ' Retrieve the Value of the Access connection string from the
            ' attributes NameValueCollection.
            Dim connectionString As String = attributes(AccessConnectionStringName)

            If Nothing = connectionString OrElse connectionString.Length = 0 Then
                Throw New Exception("The connection string was not found.")
            Else
                accessConnection = New OleDbConnection(connectionString)
            End If
            initialized = True
        End Sub 'Initialize

        ' SiteMapProvider and StaticSiteMapProvider methods that this derived class must override.
        '
        ' Clean up any collections or other state that an instance of this may hold.
        Protected Overrides Sub Clear()
            SyncLock Me
                aRootNode = Nothing
                MyBase.Clear()
            End SyncLock
        End Sub 'Clear

        ' 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

    End Class 'AccessSiteMapProvider

End Namespace

namespace Samples.AspNet.CS.Controls {

    using System;
    using System.Collections;
    using System.Collections.Specialized;
    using System.Data;
    using System.Data.OleDb;
    using System.Security.Permissions;
    using System.Web;

    /// An extremely simple AccessSiteMapProvider that only supports a
    /// site map node hierarchy 1 level deep.
    [AspNetHostingPermission(SecurityAction.Demand, Level=AspNetHostingPermissionLevel.Minimal)]
    public class AccessSiteMapProvider : StaticSiteMapProvider
    {
        private SiteMapNode rootNode =  null;
        private OleDbConnection accessConnection = null;

        // This string is case sensitive.
        private string AccessConnectionStringName = "accessSiteMapConnectionString";

        // Implement a default constructor.
        public AccessSiteMapProvider () { }

        // Some basic state to help track the initialization state of the provider.
        private bool initialized = false;
        public virtual bool IsInitialized {
            get {
                return initialized;
            }
        }
        // Return the root node of the current site map.
        public override SiteMapNode RootNode {
            get {
                SiteMapNode temp = null;
                temp = BuildSiteMap();
                return temp;
            }
        }
        protected override SiteMapNode GetRootNodeCore() {
            return RootNode;
        }
        // Initialize is used to initialize the properties and any state that the
        // AccessProvider holds, but is not used to build the site map.
        // The site map is built when the BuildSiteMap method is called.
        public override void Initialize(string name, NameValueCollection attributes) {
            if (IsInitialized)
                return;

            base.Initialize(name, attributes);

            // Create and test the connection to the Microsoft Access database.

            // Retrieve the Value of the Access connection string from the
            // attributes NameValueCollection.
            string connectionString = attributes[AccessConnectionStringName];

            if (null == connectionString || connectionString.Length == 0)
                throw new Exception ("The connection string was not found.");
            else
                accessConnection = new OleDbConnection(connectionString);

            initialized = true;
        }

        ///
        /// SiteMapProvider and StaticSiteMapProvider methods that this derived class must override.
        ///
        // Clean up any collections or other state that an instance of this may hold.
        protected override void Clear() {
            lock (this) {
                rootNode = null;
                base.Clear();
            }
        }

        // 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;
            }
        }
    }
}

C++

#using <System.Data.dll>
#using <System.Transactions.dll>
#using <System.EnterpriseServices.dll>
#using <System.dll>
#using <System.Web.dll>
#using <System.Configuration.dll>

using namespace System;
using namespace System::Collections;
using namespace System::Collections::Specialized;
using namespace System::Configuration;
using namespace System::Data;
using namespace System::Data::OleDb;
using namespace System::Security::Permissions;
using namespace System::Web;

/// An extremely simple AccessSiteMapProvider that only supports a
/// site map node hierarchy 1 level deep.

[AspNetHostingPermission(SecurityAction::Demand,Level=AspNetHostingPermissionLevel::Minimal)]
public ref class AccessSiteMapProvider: public StaticSiteMapProvider
{
private:
   SiteMapNode ^ rootNode;
   OleDbConnection^ accessConnection;

   // This string is case sensitive.
   String^ AccessConnectionStringName;

public:
   // Implement a default constructor.
   AccessSiteMapProvider()
   {
      initialized = false;
      AccessConnectionStringName = "accessSiteMapConnectionString";
   }


private:

   // Some basic state to help track the initialization state of the provider.
   bool initialized;

public:

   property bool IsInitialized 
   {
      virtual bool get()
      {
         return initialized;
      }

   }

   property SiteMapNode ^ RootNode 
   {

      // Return the root node of the current site map.
      virtual SiteMapNode ^ get() override
      {
         SiteMapNode ^ temp = nullptr;
         temp = BuildSiteMap();
         return temp;
      }

   }

protected:

   virtual SiteMapNode ^ GetRootNodeCore() override
   {
      return RootNode;
   }


public:

   // Initialize is used to initialize the properties and any state that the
   // AccessProvider holds, but is not used to build the site map.
   // The site map is built when the BuildSiteMap method is called.
   virtual void Initialize( String^ name, NameValueCollection^ attributes ) override
   {
      if ( IsInitialized )
            return;

      StaticSiteMapProvider::Initialize( name, attributes );
      
      // Create and test the connection to the Microsoft Access database.
      // Retrieve the Value of the Access connection string from the
      // attributes NameValueCollection.
      String^ connectionString = attributes[ AccessConnectionStringName ];
      if ( nullptr == connectionString || connectionString->Length == 0 )
            throw gcnew Exception( "The connection string was not found." );
      else
            accessConnection = gcnew OleDbConnection( connectionString );

      initialized = true;
   }


protected:

   ///
   /// SiteMapProvider and StaticSiteMapProvider methods that this derived class must override.
   ///
   // Clean up any collections or other state that an instance of this may hold.
   virtual void Clear() override
   {
      System::Threading::Monitor::Enter( this );
      try
      {
         rootNode = nullptr;
         StaticSiteMapProvider::Clear();
      }
      finally
      {
         System::Threading::Monitor::Exit( this );
      }

   }


public:

   // 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 );
      }

   }

};

package Samples.AspNet.JSL;
import System.*;
import System.Collections.*;
import System.Collections.Specialized.*;
import System.Data.*;
import System.Data.OleDb.*;
import System.Web.*;
import System.Configuration.*;

/// An extremely simple AccessSiteMapProvider that only supports a
/// site map node hierarchy 1 level deep.
public class AccessSiteMapProvider extends StaticSiteMapProvider
{
    private SiteMapNode rootNode = null;
    private OleDbConnection accessConnection = null;

    // This string is case sensitive.
    public String accessConnectionStringName = "accessSiteMapConnectionString";

    // Implement a default constructor.
    public AccessSiteMapProvider()
    {
    } //AccessSiteMapProvider 

    // Some basic state to help track the initialization state of the provider.
    private boolean initialized = false;

    /** @property 
     */
    public boolean get_IsInitialized()
    {
        return initialized;
    } //get_IsInitized.

    // Return the root node of the current site map.
    /** @property 
     */
    public SiteMapNode get_RootNode() throws Exception
    {
        SiteMapNode temp = null;
        temp = BuildSiteMap();
        return temp;
    } //get_RootNode

    // Initialize is used to initialize the properties and any state that the
    // AccessProvider holds, but is not used to build the site map.
    // The site map is built when the BuildSiteMap method is called.
    public void Initialize(String name, NameValueCollection attributes) 
        throws Exception
    {
        if (get_IsInitialized())
        {
            return;
        }

        super.Initialize(name, attributes);
        // Create and test the connection to the Microsoft Access database.
        // Retrieve the Value of the Access connection string from the
        // attributes NameValueCollection.
        String connectionString = attributes.get_Item(
            accessConnectionStringName);

        if (null == connectionString || connectionString.get_Length() == 0)
        {
            throw new Exception("The connection string was not found.");
        }
        else
        {
            accessConnection = new OleDbConnection(connectionString);
        }
        initialized = true;
    } //Initialize

    ///
    /// SiteMapProvider and StaticSiteMapProvider methods that this 
    /// derived class must override.
    ///
    // Clean up any collections or other state that an instance of this may hold.
    protected void Clear()
    {
        synchronized (this)
        {
            rootNode = null;
            super.Clear();
        }
    } //Clear

    // Build an in-memory representation from persistent
    // storage, and return the root node of the site map.
    public SiteMapNode BuildSiteMap() throws Exception
    {
        // Since the SiteMap class is static, make sure that it is
        // not modified while the site map is built.
        synchronized (this)
        {
            // If there is no initialization, this method is being
            // called out of order.
            if (!get_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.get_State().Equals(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.get_HasRows())
                {
                    rootNodeReader.Read();
                    rootNodeId = rootNodeReader.GetInt32(0);
                    // Create a SiteMapNode that references the current 
                    // StaticSiteMapProvider.
                    rootNode = new SiteMapNode(this,
                        ((Int32)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.set_Value((Int32)rootNodeId);
                childNodesCommand.get_Parameters().Add(rootParam);

                OleDbDataReader childNodesReader = childNodesCommand.
                    ExecuteReader();

                if (childNodesReader.get_HasRows())
                {
                    SiteMapNode childNode = null;
                    while (childNodesReader.Read())
                    {
                        childNode = new SiteMapNode(this,
                            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;
        }
    } //BuildSiteMap

    protected SiteMapNode GetRootNodeCore()
    {
        return null;
    } //GetRootNodeCore
} //AccessSiteMapProvider

Pour créer la table Access utilisée par l'exemple de code précédent comme magasin de données sitemap, publiez la requête de définition de données suivante dans une base de données Access nouvelle ou existante, puis enregistrez la base de données Access sous le nom Sitemap.mdb.

CREATE TABLE SiteMap
(
  URL Text (255) UNIQUE,
  NAME Text (255) NOT NULL,
  PARENTNODEID Int32,
    CONSTRAINT NODEID PRIMARY KEY (URL, NAME)
)

Remplissez la table avec les types de données suivants, en répertoriant les fichiers que vous avez dans votre site Web ou ceux que vous pouvez créer. Le tableau suivant affiche un exemple de liste de fichiers.

NODEID	URL	NAME	PARENTNODEID
1	Default.aspx	Par défaut	null = (cellule vide)
2	Catalog.aspx	Catalogue	1
3	Aboutus.aspx	Contactez-nous	1

Remarque
Étant donné que les sources de données diffèrent sur le plan de la syntaxe SQL, certaines commandes ne fonctionneront qu'avec une source de données particulière. Par conséquent, il vous est recommandé de créer un fournisseur sitemap spécifique à votre source de données, même si vous utilisez le fournisseur de données .NET Framework pour ODBC ou le fournisseur de données .NET Framework pour OLE DB pour accéder à votre source de données (par exemple SybaseSiteMapProvider, OracleSiteMapProvider, etc.).

Remarque

Étant donné que les sources de données diffèrent sur le plan de la syntaxe SQL, certaines commandes ne fonctionneront qu'avec une source de données particulière. Par conséquent, il vous est recommandé de créer un fournisseur sitemap spécifique à votre source de données, même si vous utilisez le fournisseur de données .NET Framework pour ODBC ou le fournisseur de données .NET Framework pour OLE DB pour accéder à votre source de données (par exemple SybaseSiteMapProvider, OracleSiteMapProvider, etc.).

La classe AccessSiteMapProvider est dérivée de la classe StaticSiteMapProvider et récupère ses informations d'une base de données Access à l'aide de requêtes SQL de base et d'objets OleDbCommand et OleDbDataReader.

Enfin, AccessSiteMapProvider est configuré pour être le fournisseur par défaut du fichier Web.config, comme le décrit l'exemple de code suivant.

<configuration>
  <system.web>
    <siteMap defaultProvider="AccessSiteMapProvider">
      <providers>
        <add 
          name="AccessSiteMapProvider"
          type="<type name>"
          accessSiteMapConnectionString="PROVIDER=MICROSOFT.JET.OLEDB.4.0;DATA SOURCE=<path>\sitemap.mdb "/>
      </providers> 
    </siteMap>
  </system.web>
</configuration>

Pour personnaliser cet exemple, remplacez <type name> par le nom qualifié complet de la classe qui implémente votre fournisseur de données sitemap. Par exemple, dans le code C# précédent, remplacez <type name> par Samples.AspNet.CS.Controls.AccessSiteMapProvider. Si vous compilez votre code de fournisseur de données sitemap et le placez dans le répertoire Bin, la chaîne <type name> doit aussi inclure le nom de votre fichier compilé sans l'extension de nom de fichier. Par exemple, si vous avez compilé le code C# ci-dessus dans un fichier appelé Samples.AspNet.dll, remplacez <type name> par Samples.AspNet.CS.Controls.AccessSiteMapProvider.Samples.AspNet. Enfin, remplacez <path> par le chemin d'accès physique absolu à votre base de données sitemap.

Remarque
Lorsque vous héritez de StaticSiteMapProvider, vous devez substituer les membres suivants : BuildSiteMap et GetRootNodeCore.

Programmation fiable

Si vous étendez la classe StaticSiteMapProvider, les trois méthodes les plus importantes sont GetRootNodeCore, Initialize et BuildSiteMap. Les méthodes Clear et FindSiteMapNode ont suffisamment d'implémentations par défaut pour toutes les implémentations de fournisseurs personnalisés.

Voir aussi

Exemple

Programmation fiable

Voir aussi

Référence

Concepts

Autres ressources