SiteMapProvider.Initialize Method (System.Web)

Initialize Method

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This page is specific to

Microsoft Visual Studio 2008/.NET Framework 3.5

Other versions are also available for the following:

.NET Framework Class Library

SiteMapProvider..::.Initialize Method

Initializes the SiteMapProvider implementation, including any resources that are needed to load site map data from persistent storage.

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

Syntax

Visual Basic (Declaration)

Public Overrides Sub Initialize ( _
    name As String, _
    attributes As NameValueCollection _
)

Visual Basic (Usage)

Dim instance As SiteMapProvider
Dim name As String
Dim attributes As NameValueCollection

instance.Initialize(name, attributes)

public override void Initialize(
    string name,
    NameValueCollection attributes
)

Visual C++

public:
virtual void Initialize(
    String^ name, 
    NameValueCollection^ attributes
) override

JScript

public override function Initialize(
    name : String, 
    attributes : NameValueCollection
)

Parameters

name: Type: System..::.String
The Name of the provider to initialize.

attributes: Type: System.Collections.Specialized..::.NameValueCollection
A NameValueCollection that can contain additional attributes to help initialize the provider. These attributes are read from the site map provider configuration in the Web.config file.

Remarks

The Initialize method does not actually build a site map, it only prepares the state of the SiteMapProvider object to do so. The default implementation initializes the SecurityTrimmingEnabled property for the site map provider from the site navigation configuration.

Classes that derive from the SiteMapProvider can override the Initialize method to initialize any state and resources that are required to load site map data from persistent storage. For example, if your derived class is using files to store site map data, any file initialization can be performed in the Initialize method. If the derived class uses some other type of data store, such as a relational database, initializing a database connection might be performed.

Additional attributes, such as file names or connection strings, are read by the ASP.NET configuration system and passed to the Initialize method with its NameValueCollection parameter.

Notes to Inheritors:

When overriding the Initialize method in a derived class, be sure to first call the Initialize method for the base class before performing your own initializations.

Examples

The following code example demonstrates how to override the Initialize method to prepare a Microsoft Access database connection.

The connection string for the OleDbConnection object is passed in the NameValueCollection parameter of the Initialize method. In this case, the connection string is provided by the provider-specific section in the Web.config file. Here, accessSiteMapConnectionString contains a connection string to a Microsoft Access database that hosts the site map data.

<siteMap defaultProvider="AccessSiteMapProvider">
  <providers>
     <add
       name="AccessSiteMapProvider"
       type="Samples.AspNet.AccessSiteMapProvider,Samples.AspNet"
       accessSiteMapConnectionString="PROVIDER=MICROSOFT.JET.OLEDB.4.0;DATA SOURCE=\\SomeUNCShare\\sitemap.mdb"/>
  </providers> 
 </siteMap>

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

Visual Basic

' 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

// 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;
}

Visual C++

   // 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:

Platforms

Windows 7, Windows Vista, Windows XP SP2, Windows XP Media Center Edition, Windows XP Professional x64 Edition, Windows XP Starter Edition, Windows Server 2008 R2, Windows Server 2008, Windows Server 2003, Windows Server 2000 SP4, Windows Millennium Edition, Windows 98

The .NET Framework and .NET Compact Framework do not support all versions of every platform. For a list of the supported versions, see .NET Framework System Requirements.

Version Information

.NET Framework

Supported in: 3.5, 3.0, 2.0

Reference

SiteMapProvider Class

SiteMapProvider Members