ASP.NET

Dynamic User Control - RaiseEvent Fires every second postback RSS

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Last post Mar 30, 2009 07:34 PM by anjop

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wmin

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2 Points

3 Posts

Dynamic User Control - RaiseEvent Fires every second postback

Feb 09, 2009 06:12 PM|LINK

Hi, I have created user control that raises an event from dynamicaly generated buttons that should be picked up by the parent, however, event fires every second postback and I have no idea why.

=============================
User control:  tab_menu.ascx.vb
=============================
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.UI.HtmlControls

Partial Class tab_menu
    Inherits System.Web.UI.UserControl

    Public Event Updated(ByVal sender As Object, ByVal e As EventArgs)
    Private Lst As New ListDictionary
    Private strSelection As String

    Public WriteOnly Property MenuList() As ListDictionary
        Set(ByVal value As ListDictionary)
            Lst = value
        End Set
    End Property

    Public WriteOnly Property Selection() As String
        Set(ByVal value As String)
            strSelection = value
        End Set
    End Property

    Private Sub EvokeClick(ByVal sender As Object, ByVal e As System.EventArgs)

        MsgBox("Raising Event")
        RaiseEvent Updated(sender, e)

    End Sub

    Protected Sub tbl_TabMenu_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles tbl_TabMenu.Load
        Dim Cell As TableCell
        Dim Row As New TableRow
        Dim Link As LinkButton

        Dim de As DictionaryEntry

        MsgBox(strSelection & ":Child")

        For Each de In Lst
            Cell = New TableCell
            Link = New LinkButton

            Cell.Text = de.Key
            Cell.Width = 81
            Cell.Height = 23
            Cell.Style("text-align") = "center"

            If de.Key = strSelection Then
                Cell.Style("background-image") = "Images/tab_active.gif"
            Else
                Cell.Style("background-image") = "Images/tab_idle.gif"
            End If

            Link.ID = de.Key
            Link.Text = de.Key
            AddHandler Link.Click, AddressOf EvokeClick
            Link.DataBind()

            Cell.Controls.Add(Link)
            Row.Controls.Add(Cell)

        Next de

        tbl_TabMenu.Controls.Add(Row)
    End Sub
End Class
=============================
Parent:
=============================
Imports System.IO
Imports System.Web.UI
Imports System.Web.UI.WebControls
Imports System.Web.HttpContext
Imports System.Web.UI.HtmlControls

Partial Class _Default
    Inherits System.Web.UI.Page

    Delegate Sub _delTabHandler(ByVal myStr As String)

    Dim strSelection As String

    Dim WithEvents oCtrlTabMenu As ASP.tab_menu = CType(LoadControl("tab_menu.ascx"), ASP.tab_menu)
    Protected oCtrlCompanyForm As ASP.ecompanyaddresstab_ascx = CType(LoadControl("eCompanyAddressTab.ascx"), ASP.ecompanyaddresstab_ascx)
    Protected oCtrlCompProf As ASP.ecompanyprofile_ascx = CType(LoadControl("eCompanyProfile.ascx"), ASP.ecompanyprofile_ascx)

    Protected Sub Page_Init(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
        ReloadControl("")
    End Sub

    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load

        If Not IsPostBack Then
            ' RetrieveCompany()
        End If
    End Sub

    Sub Company_Click(ByVal str As String)
        phForm.Controls.Clear()
        phForm.Controls.Add(oCtrlCompanyForm)

        ReloadControl(str)
    End Sub

    Sub Profile_Click(ByVal str As String)

        phForm.Controls.Clear()
        phForm.Controls.Add(oCtrlCompProf)

       ReloadControl(str)

    End Sub



    Sub TabMenu_Initialise(ByVal sender As Object, ByVal e As System.EventArgs) Handles oCtrlTabMenu.Updated
        Dim str As String = sender.id.ToString

        MsgBox("TBINIT: " & str)
        Select Case str
            Case "Profile" : Profile_Click(str)
            Case "Logos" : Logos_Click(str)
            Case "Company" : Company_Click(str)
        End Select

    End Sub

    Sub ReloadControl(ByVal str As String)

        Dim Lst As New ListDictionary
        Lst.Add("Company", "")
        Lst.Add("Profile", "")
        Lst.Add("Logos", "")

        oCtrlTabMenu.Selection = str
        oCtrlTabMenu.MenuList = Lst

        'phTabMenu.Controls.Clear()
        phTabMenu.Controls.Add(oCtrlTabMenu)

    End Sub

VB .NET ASP.NET event usercontrol asp.net 2.0 asp.net 2.0 VB 2008 asp.net2.0 control Delegation User Controls Events RaiseEvent
- Edited by wmin on Feb 10, 2009 01:19 AM
- Edited by wmin on Feb 10, 2009 01:21 AM
- Edited by wmin on Feb 10, 2009 01:21 AM
- Moved by mbanavige on Apr 01, 2009 10:28 AM
- Reply
wmin

Member

2 Points

3 Posts

Re: Dynamic User Control - RaiseEvent Fires every second postback

Feb 10, 2009 12:22 PM|LINK

The soulution seems to be here: http://stackoverflow.com/questions/310002/events-on-aspnet-usercontrol-raise-every-other-click

It looks like the problem is arising because my user control is recreated on each page reload - instead of being rebound.

How do i rebind it?

vb.net ASP.NET rebinding user control fire event postback
- Reply
ixtli

Participant

1812 Points

318 Posts

Re: Dynamic User Control - RaiseEvent Fires every second postback

Feb 16, 2009 02:56 AM|LINK

TRY TO LOAD THE USERCONTROL AT PAGE_PREINIT EVENT
- Reply
anjop

Member

2 Points

1 Post

Re: Dynamic User Control - RaiseEvent Fires every second postback

Mar 30, 2009 07:34 PM|LINK

This behavior occurs because the user control changes name after the first postback. (i.e. "_ctl1" changes to "_ctl0", see client source code)

If you overrides "ClientID" and "UniqueID" forcing both to return a predefined value, you can resolve this trouble

see http://www.west-wind.com/WebLog/posts/4605.aspx