SiteMapProvider.Initialize(String, NameValueCollection) 方法

定義

命名空間:

System.Web

組件:

System.Web.dll

初始化 SiteMapProvider 實作，包括從持續性儲存體載入網站導覽資料時所需的任何資源。

public:
 override void Initialize(System::String ^ name, System::Collections::Specialized::NameValueCollection ^ attributes);

public override void Initialize (string name, System.Collections.Specialized.NameValueCollection attributes);

override this.Initialize : string * System.Collections.Specialized.NameValueCollection -> unit

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

參數

name

String

要初始化之提供者的 Name。

attributes

NameValueCollection

NameValueCollection，可以包含用來協助初始化提供者的其他屬性。 這些屬性是從 Web.config 檔案中的網站導覽提供者組態讀取。

範例

下列程式碼範例示範如何覆寫 Initialize 方法來準備 Microsoft Access 資料庫連線。

物件的連接字串 OleDbConnection 會在 方法的 Initialize 參數中 NameValueCollection 傳遞。 在此情況下，連接字串是由Web.config檔案中的提供者特定區段所提供。 在這裡， accessSiteMapConnectionString 包含裝載網站地圖資料的 Microsoft Access 資料庫的連接字串。

<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>  

此程式碼範例是提供給 類別之較大範例的 SiteMapProvider 一部分。

   // 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:

// 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;
}

' 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

備註

方法 Initialize 實際上不會建置網站地圖，只會準備物件的狀態 SiteMapProvider 來執行此動作。 預設實作會 SecurityTrimmingEnabled 從網站導覽組態初始化網站地圖提供者的屬性。

衍生自 的 SiteMapProvider 類別可以覆寫 方法， Initialize 以初始化從永續性儲存體載入網站地圖資料所需的任何狀態和資源。 例如，如果您的衍生類別使用檔案來儲存網站地圖資料，則可以在 Initialize 方法中執行任何檔案初始化。 如果衍生類別使用某種其他類型的資料存放區，例如關係資料庫，可能會執行資料庫連接初始化。

ASP.NET 組態系統會讀取其他屬性，例如檔案名或連接字串，並使用其 NameValueCollection 參數傳遞至 Initialize 方法。

給繼承者的注意事項

在 Initialize(String, NameValueCollection) 衍生類別中覆寫 方法時，請務必先呼叫 Initialize(String, NameValueCollection) 基類的方法，再執行您自己的初始化。

另請參閱

• ProviderBase
• BuildSiteMap()
• Clear()