SiteMap.SiteMapResolve Kejadian

Definisi

Ruang nama:

System.Web

Rakitan:

System.Web.dll

Terjadi ketika CurrentNode properti diakses.

public:
 static event System::Web::SiteMapResolveEventHandler ^ SiteMapResolve;

public static event System.Web.SiteMapResolveEventHandler SiteMapResolve;

member this.SiteMapResolve : System.Web.SiteMapResolveEventHandler 

Public Shared Custom Event SiteMapResolve As SiteMapResolveEventHandler 

Jenis Acara

SiteMapResolveEventHandler

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 konteks.

Catatan

Infrastruktur navigasi situs ASP.NET melindungi dari rekursi tak terbatas, yang memberikan perlindungan dan meminimalkan risiko keamanan yang terkait dengan mengakses CurrentNode properti dari dalam SiteMapResolveEventHandler kelas.

Kode berikut termasuk dalam file Global.asax. Penanganan aktivitas hanya akan dilampirkan sekali untuk aplikasi. Kode mengenali apakah halaman mengimplementasikan ISiteMapResolver antarmuka. Jika antarmuka diimplementasikan, ExpandForumPaths fungsi dipanggil.

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

Kode berikut mendefinisikan antarmuka terpisah. (Dalam proyek situs Web, Anda dapat meletakkan kode ini di folder App_Code.) Antarmuka ISiteMapResolver mendefinisikan ExpandForumPaths metode .

// These methods are just placeholders for the example.
// One option is to use the HttpContext or e.Context object
// to obtain the ID.
private int GetMostRecentForumGroupID()
{
    return 24;
}

private int GetMostRecentForumID(int forumGroupId)
{
    return 128;
}

private int GetMostRecentPostID(int forumId)
{
    return 317424;
}

' These methods are just placeholders for the example.
' One option is to use the HttpContext or e.Context object
' to obtain the ID.
Private Function GetMostRecentForumGroupID() As Integer
    Return 24
End Function

Private Function GetMostRecentForumID(ByVal forumGroupId As Integer) As Integer
    Return 128
End Function

Private Function GetMostRecentPostID(ByVal forumId As Integer) As Integer
    Return 317424
End Function

Kode berikut termasuk dalam halaman yang setidaknya memiliki tiga simpul dalam struktur peta situs. Halaman mengimplementasikan ISiteMapResolver antarmuka, yang memungkinkan metode dipanggil ExpandForumPaths .

<asp:SiteMapPath
id="SiteMapPath1"
runat="server"
RenderCurrentNodeAsLink="true" />

<asp:SiteMapPath
id="SiteMapPath1"
runat="server"
RenderCurrentNodeAsLink="true" />

Keterangan

Pelanggan melampirkan SiteMapResolveEventHandler objek ke peristiwa statis SiteMapResolve untuk menerima pemberitahuan saat CurrentNode properti diakses. Ini memungkinkan pengguna untuk menerapkan logika kustom saat membuat SiteMapNode representasi halaman yang saat ini dijalankan tanpa memerlukan implementasi penyedia kustom.

Jika Anda berlangganan acara, SiteMapResolve Anda juga berlangganan SiteMapResolve peristiwa di penyedia peta situs default.

Lihat juga

• SiteMapResolveEventHandler
• SiteMapResolveEventArgs