SiteMapPath.OnItemCreated(SiteMapNodeItemEventArgs) 方法
定義
重要
部分資訊涉及發行前產品,在發行之前可能會有大幅修改。 Microsoft 對此處提供的資訊,不做任何明確或隱含的瑕疵擔保。
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
包含事件資料的 SiteMapNodeItemEventArgs。
範例
下列程式代碼範例示範如何在 方法內InitializeItem建立 SiteMapNodeItem 之後呼叫 OnItemCreated 方法。 此程式代碼範例是針對 類別提供的較大範例的 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
在 ItemCreated 控件建立 SiteMapNodeItem之後SiteMapPath會引發 事件,這是代表SiteMapNode的 Web 伺服器控件,並將它與 SiteMapNode產生關聯。 在建立的節點項目系結至其數據之前,會 OnItemCreated 呼叫 方法。 這可讓您提供事件處理方法,以在建立 時 SiteMapNodeItem 執行自定義例程。
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。