SiteMapPath.OnItemCreated(SiteMapNodeItemEventArgs) 方法

定义

命名空间:

System.Web.UI.WebControls

程序集:

System.Web.dll

引发 SiteMapPath 控件的 ItemCreated 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)

参数

e

SiteMapNodeItemEventArgs

包含事件数据的 SiteMapNodeItemEventArgs。

示例

下面的代码示例演示如何在 方法中创建 SiteMapNodeItemInitializeItem 后调用 OnItemCreated 方法。 此代码示例是为 SiteMapPath 类提供的一个更大示例的一部分。

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

注解

该 ItemCreated 事件在 SiteMapPath 控件创建 SiteMapNodeItem后引发，该控件是表示 SiteMapNode的 Web 服务器控件，并将其关联到 SiteMapNode。 在 OnItemCreated 创建的节点项绑定到其数据之前调用 方法。 这允许你提供一个事件处理方法，该方法在创建 SiteMapNodeItem 时执行自定义例程。

引发事件时，将通过委托调用事件处理程序。 有关详细信息，请参阅 处理和引发事件。

OnItemCreated 方法还允许派生类对事件进行处理而不必附加委托。 这是在派生类中处理事件的首选技术。

继承者说明

在派生类中重写 OnItemCreated(SiteMapNodeItemEventArgs) 时，一定要调用基类的 OnItemCreated(SiteMapNodeItemEventArgs) 方法，以便已注册的委托对事件进行接收。

另请参阅

• OnItemDataBound(SiteMapNodeItemEventArgs)
• SiteMapPath Web 服务器控件