SiteMapPath.OnItemCreated(SiteMapNodeItemEventArgs) 方法

定義

命名空間:

System.Web.UI.WebControls

組件:

System.Web.dll

引發 ItemCreated 控制項的 SiteMapPath 事件。

protected:
 virtual void OnItemCreated(System::Web::UI::WebControls::SiteMapNodeItemEventArgs ^ e);

protected virtual void OnItemCreated (System.Web.UI.WebControls.SiteMapNodeItemEventArgs e);

abstract member OnItemCreated : System.Web.UI.WebControls.SiteMapNodeItemEventArgs -> unit
override this.OnItemCreated : System.Web.UI.WebControls.SiteMapNodeItemEventArgs -> unit

Protected Overridable Sub OnItemCreated (e As SiteMapNodeItemEventArgs)

參數

e

SiteMapNodeItemEventArgs

包含事件資料的 SiteMapNodeItemEventArgs。

範例

下列程式碼範例示範如何在 方法內 InitializeItem 建立 SiteMapNodeItem 之後呼叫 OnItemCreated 方法。 此程式碼範例是提供給 類別之較大範例的 SiteMapPath 一部分。

private void AddDropDownListAfterCurrentNode(SiteMapNodeItem item) {

    SiteMapNodeCollection childNodes = item.SiteMapNode.ChildNodes;

    // Only do this work if there are child nodes.
    if (childNodes != null) {

        // Add another PathSeparator after the CurrentNode.
        SiteMapNodeItem finalSeparator =
            new SiteMapNodeItem(item.ItemIndex,
                                SiteMapNodeItemType.PathSeparator);

        SiteMapNodeItemEventArgs eventArgs =
            new SiteMapNodeItemEventArgs(finalSeparator);

        InitializeItem(finalSeparator);
        // Call OnItemCreated every time a SiteMapNodeItem is
        // created and initialized.
        OnItemCreated(eventArgs);

        // The pathSeparator does not bind to any SiteMapNode, so
        // do not call DataBind on the SiteMapNodeItem.
        item.Controls.Add(finalSeparator);

        // Create a DropDownList and populate it with the children of the
        // CurrentNode. There are no styles or templates that are applied
        // to the DropDownList control. If OnSelectedIndexChanged is raised,
        // the event handler redirects to the page selected.
        // The CurrentNode has child nodes.
        DropDownList ddList = new DropDownList();
        ddList.AutoPostBack = true;

        ddList.SelectedIndexChanged += new EventHandler(this.DropDownNavPathEventHandler);

        // Add a ListItem to the DropDownList for every node in the
        // SiteMapNodes collection.
        foreach (SiteMapNode node in childNodes) {
            ddList.Items.Add(new ListItem(node.Title, node.Url));
        }

        item.Controls.Add(ddList);
    }
}

Private Sub AddDropDownListAfterCurrentNode(item As SiteMapNodeItem)

   Dim childNodes As SiteMapNodeCollection = item.SiteMapNode.ChildNodes

   ' Only do this work if there are child nodes.
   If Not (childNodes Is Nothing) Then

      ' Add another PathSeparator after the CurrentNode.
      Dim finalSeparator As New SiteMapNodeItem(item.ItemIndex, SiteMapNodeItemType.PathSeparator)

      Dim eventArgs As New SiteMapNodeItemEventArgs(finalSeparator)

      InitializeItem(finalSeparator)
      ' Call OnItemCreated every time a SiteMapNodeItem is
      ' created and initialized.
      OnItemCreated(eventArgs)

      ' The pathSeparator does not bind to any SiteMapNode, so
      ' do not call DataBind on the SiteMapNodeItem.
      item.Controls.Add(finalSeparator)

      ' Create a DropDownList and populate it with the children of the
      ' CurrentNode. There are no styles or templates that are applied
      ' to the DropDownList control. If OnSelectedIndexChanged is raised,
      ' the event handler redirects to the page selected.
      ' The CurrentNode has child nodes.
      Dim ddList As New DropDownList()
      ddList.AutoPostBack = True

      AddHandler ddList.SelectedIndexChanged, AddressOf Me.DropDownNavPathEventHandler

      ' Add a ListItem to the DropDownList for every node in the
      ' SiteMapNodes collection.
      Dim node As SiteMapNode
      For Each node In  childNodes
         ddList.Items.Add(New ListItem(node.Title, node.Url))
      Next node

      item.Controls.Add(ddList)
   End If
End Sub

備註

此 ItemCreated 事件會在 控制項建立 SiteMapNodeItem 之後 SiteMapPath 引發，這是代表 SiteMapNode 的 Web 服務器控制項，並將它 SiteMapNode 與 產生關聯。 方法 OnItemCreated 會在建立的節點專案系結至其資料之前呼叫。 這可讓您提供事件處理方法，以在建立 SiteMapNodeItem 時執行自訂常式。

引發事件會透過委派叫用此事件處理常式。 如需詳細資訊，請參閱 處理和引發事件。

OnItemCreated 方法也允許衍生類別處理事件，而不用附加委派。 這是在衍生類別中處理事件的慣用技巧。

給繼承者的注意事項

當在衍生類別中覆寫 OnItemCreated(SiteMapNodeItemEventArgs) 時，請確定呼叫基底類別的 OnItemCreated(SiteMapNodeItemEventArgs) 方法，使已註冊的委派能接收到事件。

另請參閱

• OnItemDataBound(SiteMapNodeItemEventArgs)
• SiteMapPath Web 服務器控制項