SiteMapResolveEventHandler Delegasikan

Definisi

Ruang nama:

System.Web

Rakitan:

System.Web.dll

Mewakili metode yang akan menangani SiteMapResolve peristiwa instans tertentu dari SiteMapProvider kelas statis SiteMap atau .

public delegate System::Web::SiteMapNode ^ SiteMapResolveEventHandler(System::Object ^ sender, SiteMapResolveEventArgs ^ e);

public delegate System.Web.SiteMapNode SiteMapResolveEventHandler(object sender, SiteMapResolveEventArgs e);

type SiteMapResolveEventHandler = delegate of obj * SiteMapResolveEventArgs -> SiteMapNode

Public Delegate Function SiteMapResolveEventHandler(sender As Object, e As SiteMapResolveEventArgs) As SiteMapNode 

Parameter

sender

Object

Sumber peristiwa, instans SiteMapProvider kelas.

e

SiteMapResolveEventArgs

SiteMapResolveEventArgs yang berisi data peristiwa.

Tampilkan Nilai

SiteMapNode

SiteMapNode yang mewakili hasil SiteMapResolveEventHandler operasi.

Contoh

Contoh kode berikut menunjukkan cara menangani SiteMapResolve peristiwa di halaman web ASP.NET untuk mengubah URL target yang ditampilkan oleh kontrol navigasi situs, seperti SiteMapPath kontrol. Dalam contoh ini, halaman saat ini adalah halaman posting di papan buletin online atau forum. Untuk merender navigasi situs yang lebih bermakna, URL simpul yang ditampilkan oleh kontrol navigasi ditambahkan dengan string kueri yang relevan dengan konteks.

Catatan

Anda dapat mengakses CurrentNode properti dari dalam SiteMapResolveEventHandler kelas dengan aman. Infrastruktur navigasi situs ASP.NET melindungi dari rekursi tak terbatas, dalam hal ini.

private void Page_Load(object sender, EventArgs e)
{
    // The ExpandForumPaths method is called to handle
    // the SiteMapResolve event.
    SiteMap.SiteMapResolve +=
      new SiteMapResolveEventHandler(this.ExpandForumPaths);
}

private SiteMapNode ExpandForumPaths(Object sender, SiteMapResolveEventArgs e)
{
    // The current node represents a Post page in a bulletin board forum.
    // Clone the current node and all of its relevant parents. This
    // returns a site map node that a developer can then
    // walk, modifying each node.Url property in turn.
    // Since the cloned nodes are separate from the underlying
    // site navigation structure, the fixups that are made do not
    // effect the overall site navigation structure.
    SiteMapNode currentNode = SiteMap.CurrentNode.Clone(true);
    SiteMapNode tempNode = currentNode;

    // Obtain the recent IDs.
    int forumGroupID = GetMostRecentForumGroupID();
    int forumID = GetMostRecentForumID(forumGroupID);
    int postID = GetMostRecentPostID(forumID);

    // The current node, and its parents, can be modified to include
    // dynamic querystring information relevant to the currently
    // executing request.
    if (0 != postID)
    {
        tempNode.Url = tempNode.Url + "?PostID=" + postID.ToString();
    }

    if ((null != (tempNode = tempNode.ParentNode)) &&
        (0 != forumID))
    {
        tempNode.Url = tempNode.Url + "?ForumID=" + forumID.ToString();
    }

    if ((null != (tempNode = tempNode.ParentNode)) &&
        (0 != forumGroupID))
    {
        tempNode.Url = tempNode.Url + "?ForumGroupID=" + forumGroupID.ToString();
    }

    return currentNode;
}

Private Sub Page_Load(ByVal sender As Object, ByVal e As EventArgs)

    ' The ExpandForumPaths method is called to handle
    ' the SiteMapResolve event.
    AddHandler SiteMap.SiteMapResolve, AddressOf Me.ExpandForumPaths

End Sub

Private Function ExpandForumPaths(ByVal sender As Object, ByVal e As SiteMapResolveEventArgs) As SiteMapNode
    ' The current node represents a Post page in a bulletin board forum.
    ' Clone the current node and all of its relevant parents. This
    ' returns a site map node that a developer can then
    ' walk, modifying each node.Url property in turn.
    ' Since the cloned nodes are separate from the underlying
    ' site navigation structure, the fixups that are made do not
    ' effect the overall site navigation structure.
    Dim currentNode As SiteMapNode = SiteMap.CurrentNode.Clone(True)
    Dim tempNode As SiteMapNode = currentNode

    ' Obtain the recent IDs.
    Dim forumGroupID As Integer = GetMostRecentForumGroupID()
    Dim forumID As Integer = GetMostRecentForumID(forumGroupID)
    Dim postID As Integer = GetMostRecentPostID(forumID)

    ' The current node, and its parents, can be modified to include
    ' dynamic querystring information relevant to the currently
    ' executing request.
    If Not (0 = postID) Then
        tempNode.Url = tempNode.Url & "?PostID=" & postID.ToString()
    End If

    tempNode = tempNode.ParentNode
    If Not (0 = forumID) And Not (tempNode Is Nothing) Then
        tempNode.Url = tempNode.Url & "?ForumID=" & forumID.ToString()
    End If

    tempNode = tempNode.ParentNode
    If Not (0 = ForumGroupID) And Not (tempNode Is Nothing) Then
        tempNode.Url = tempNode.Url & "?ForumGroupID=" & forumGroupID.ToString()
    End If

    Return currentNode

End Function

Keterangan

Kelas statis SiteMap mengekspos SiteMapResolve peristiwa penyedia peta situs default.

Saat membuat SqlDataSourceCommandEventHandler delegasi, Anda mengidentifikasi metode yang akan menangani peristiwa. Untuk mengaitkan peristiwa dengan penanganan aktivitas Anda, tambahkan instans delegasi ke peristiwa. Penanganan aktivitas dipanggil setiap kali peristiwa terjadi, kecuali Anda menghapus delegasi. Untuk informasi selengkapnya tentang delegasi penanganan aktivitas, lihat Menangani dan Menaikkan Peristiwa.

Metode Ekstensi

GetMethodInfo(Delegate)

Mendapatkan objek yang mewakili metode yang diwakili oleh delegasi yang ditentukan.

Lihat juga

• SiteMapResolveEventArgs
• SiteMapResolve