handling buttons within repeater control

[Jorge Ayala]

Well I'm trying to catch and act upon a button event that is placed within
the item template of a repeater control. Yet the code I'm using isn't
working. What I've seen out there to explain how to do this is way
complicated and assumes a familiarity with dot net that I don't have yet.
I'll get it eventually but this is where I'll get it. Here's my code.
First part is the user control and second is the code behind page
Use control

<%@ Control Language="vb" AutoEventWireup="false"
Codebehind="SiteList.ascx.vb" Inherits="GSIComputerServices.SiteList"
TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>
<asp:Repeater id="SiteRepeater" runat="server"
OnItemCommand="SiteRepeater_ItemCommand">
<ItemTemplate>
<tr>
<td>
<asp:Button Text='<%#
CType(Databinder.Eval(Container.DataItem,"SiteName "),String).Trim %>'
Runat="server" Font-Bold=True CommandArgument='<%#
CType(Databinder.Eval(Container.DataItem,"SiteID") ,String).Trim()%>'
CommandName='SiteIDButton' Width="100px">
</asp:Button>
</td>
</tr>
</ItemTemplate>
<HeaderTemplate>
<table border="0" cellpadding="0" cellspacing="0">
</HeaderTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
<SeparatorTemplate>
</SeparatorTemplate>
</asp:Repeater>

code behind
Imports System.Data.SqlClient

Imports System.Data

Imports GSIComputerServices

Public Class SiteList

Inherits System.Web.UI.UserControl

Dim useparent As Master

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.

<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()

End Sub

Protected WithEvents SiteRepeater As System.Web.UI.WebControls.Repeater

Protected WithEvents LinkButton1 As System.Web.UI.WebControls.LinkButton

'NOTE: The following placeholder declaration is required by the Web Form
Designer.

'Do not delete or move it.

Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Init

'CODEGEN: This method call is required by the Web Form Designer

'Do not modify it using the code editor.

InitializeComponent()

End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

Dim sql As String

Dim db As SqlConnection

Dim comm As SqlCommand

Dim dread As SqlDataReader

sql = "Select * From _Site where MasterID = " &
CType(Session.Contents("MasterID"), Integer) & ""

db = New SqlConnection("")

db.Open()

comm = New SqlCommand(sql, db)

dread = comm.ExecuteReader

Me.SiteRepeater.DataSource = dread

Me.SiteRepeater.DataBind()

db.Close()

'Put user code to initialize the page here

End Sub

Public Sub ChooseSite(ByVal siteID As String)

Me.useparent.ChooseSite(siteID)

End Sub

Public Property componentParent() As Master

Get

Return Me.useparent

End Get

Set(ByVal Value As Master)

Me.useparent = Value

End Set

End Property

Public Sub SiteRepeater_ItemCommand(ByVal source As Object, ByVal e As
System.Web.UI.WebControls.RepeaterCommandEventArgs ) Handles
SiteRepeater.ItemCommand

'ChooseSite("all")

ChooseSite(CType(e.CommandArgument(), String))

End Sub

End Class

[Teemu Keiski]

Hi,

you seem to be databinding the grid on every request and that's why
ItemCommand event wouldn't be raised on postback (because it is cleared on
rebinding when rebinding happens "too early").

Put the code that bind the grid in Page_Load inside:

If Not Page.IsPostBack Then
'code to bind here
End If

and ItemCommand event starts to raise.

--
Teemu Keiski
MCP, Microsoft MVP (ASP.NET), AspInsiders member
ASP.NET Forum Moderator, AspAlliance Columnist
"Jorge Ayala" <jo***@gsicomputerservices.com> wrote in message
news:uO**************@tk2msftngp13.phx.gbl...

Well I'm trying to catch and act upon a button event that is placed within
the item template of a repeater control. Yet the code I'm using isn't
working. What I've seen out there to explain how to do this is way
complicated and assumes a familiarity with dot net that I don't have yet.
I'll get it eventually but this is where I'll get it. Here's my code.
First part is the user control and second is the code behind page
Use control

<%@ Control Language="vb" AutoEventWireup="false"
Codebehind="SiteList.ascx.vb" Inherits="GSIComputerServices.SiteList"
TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>
<asp:Repeater id="SiteRepeater" runat="server"
OnItemCommand="SiteRepeater_ItemCommand">
<ItemTemplate>
<tr>
<td>
<asp:Button Text='<%#
CType(Databinder.Eval(Container.DataItem,"SiteName "),String).Trim %>'
Runat="server" Font-Bold=True CommandArgument='<%#
CType(Databinder.Eval(Container.DataItem,"SiteID") ,String).Trim()%>'
CommandName='SiteIDButton' Width="100px">
</asp:Button>
</td>
</tr>
</ItemTemplate>
<HeaderTemplate>
<table border="0" cellpadding="0" cellspacing="0">
</HeaderTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
<SeparatorTemplate>
</SeparatorTemplate>
</asp:Repeater>

code behind
Imports System.Data.SqlClient

Imports System.Data

Imports GSIComputerServices

Public Class SiteList

Inherits System.Web.UI.UserControl

Dim useparent As Master

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.

<System.Diagnostics.DebuggerStepThrough()> Private Sub InitializeComponent()
End Sub

Protected WithEvents SiteRepeater As System.Web.UI.WebControls.Repeater

Protected WithEvents LinkButton1 As System.Web.UI.WebControls.LinkButton

'NOTE: The following placeholder declaration is required by the Web Form
Designer.

'Do not delete or move it.

Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Init

'CODEGEN: This method call is required by the Web Form Designer

'Do not modify it using the code editor.

InitializeComponent()

End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load

Dim sql As String

Dim db As SqlConnection

Dim comm As SqlCommand

Dim dread As SqlDataReader

sql = "Select * From _Site where MasterID = " &
CType(Session.Contents("MasterID"), Integer) & ""

db = New SqlConnection("")

db.Open()

comm = New SqlCommand(sql, db)

dread = comm.ExecuteReader

Me.SiteRepeater.DataSource = dread

Me.SiteRepeater.DataBind()

db.Close()

'Put user code to initialize the page here

End Sub

Public Sub ChooseSite(ByVal siteID As String)

Me.useparent.ChooseSite(siteID)

End Sub

Public Property componentParent() As Master

Get

Return Me.useparent

End Get

Set(ByVal Value As Master)

Me.useparent = Value

End Set

End Property

Public Sub SiteRepeater_ItemCommand(ByVal source As Object, ByVal e As
System.Web.UI.WebControls.RepeaterCommandEventArgs ) Handles
SiteRepeater.ItemCommand

'ChooseSite("all")

ChooseSite(CType(e.CommandArgument(), String))

End Sub

End Class

[Adrijan Josic]

Actually I databind() repeaters on each Page_Load, I never
check for IsPostBack and it works just fine... Infact if
you have an OnItemDataBound event that dynamically adds
buttons into your Repeater Items you HAVE TO databind() on
each Page_Load or the dynamically created button will
disappear at post back, so you have to recreate it at each
page load so the ItemCommand triggers...

the problem here which i noticed also is actually a bug.
Button ItemCommand events are NOT bubbled to their parent
Repeater. LinkButtons are. It is quite frustrating because
in help it clearly states Buttons are supposed to work
this way and they don't, they never fire the ItemCommand
event.. LinkButtons do... Maybe it has something to do
with Buttons generating input type=submit and LinkButtons
generate javascript:do_submit or something like that..

anyway, something is definitely wrong here... try it out..

-----Original Message-----
Hi,

you seem to be databinding the grid on every request and that's whyItemCommand event wouldn't be raised on postback (because it is cleared onrebinding when rebinding happens "too early").

Put the code that bind the grid in Page_Load inside:

If Not Page.IsPostBack Then
'code to bind here
End If

and ItemCommand event starts to raise.

--
Teemu Keiski
MCP, Microsoft MVP (ASP.NET), AspInsiders member
ASP.NET Forum Moderator, AspAlliance Columnist
"Jorge Ayala" <jo***@gsicomputerservices.com> wrote in messagenews:uO**************@tk2msftngp13.phx.gbl...

Well I'm trying to catch and act upon a button event that is placed within the item template of a repeater control. Yet the code I'm using isn't working. What I've seen out there to explain how to do this is way complicated and assumes a familiarity with dot net that I don't have yet. I'll get it eventually but this is where I'll get it. Here's my code. First part is the user control and second is the code behind page

Use control

<%@ Control Language="vb" AutoEventWireup="false"
Codebehind="SiteList.ascx.vb" Inherits="GSIComputerServices.SiteList" TargetSchema="http://schemas.microsoft.com/intellisense/ie5
" %> <asp:Repeater id="SiteRepeater" runat="server"
OnItemCommand="SiteRepeater_ItemCommand">
<ItemTemplate>
<tr>
<td>
<asp:Button Text='<%#
CType(Databinder.Eval (Container.DataItem,"SiteName"),String).Trim %>' Runat="server" Font-Bold=True CommandArgument='<%#
CType(Databinder.Eval (Container.DataItem,"SiteID"),String).Trim()%>' CommandName='SiteIDButton' Width="100px">
</asp:Button>
</td>
</tr>
</ItemTemplate>
<HeaderTemplate>
<table border="0" cellpadding="0" cellspacing="0">
</HeaderTemplate>
<FooterTemplate>
</table>
</FooterTemplate>
<SeparatorTemplate>
</SeparatorTemplate>
</asp:Repeater>

code behind
Imports System.Data.SqlClient

Imports System.Data

Imports GSIComputerServices

Public Class SiteList

Inherits System.Web.UI.UserControl

Dim useparent As Master

#Region " Web Form Designer Generated Code "

'This call is required by the Web Form Designer.

<System.Diagnostics.DebuggerStepThrough()> Private Sub

InitializeComponent()

End Sub

Protected WithEvents SiteRepeater As System.Web.UI.WebControls.Repeater
Protected WithEvents LinkButton1 As System.Web.UI.WebControls.LinkButton
'NOTE: The following placeholder declaration is required by the Web Form Designer.

'Do not delete or move it.

Private designerPlaceholderDeclaration As System.Object

Private Sub Page_Init(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Init

'CODEGEN: This method call is required by the Web Form Designer
'Do not modify it using the code editor.

InitializeComponent()

End Sub

#End Region

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As System.EventArgs) Handles MyBase.Load

Dim sql As String

Dim db As SqlConnection

Dim comm As SqlCommand

Dim dread As SqlDataReader

sql = "Select * From _Site where MasterID = " &
CType(Session.Contents("MasterID"), Integer) & ""

db = New SqlConnection("")

db.Open()

comm = New SqlCommand(sql, db)

dread = comm.ExecuteReader

Me.SiteRepeater.DataSource = dread

Me.SiteRepeater.DataBind()

db.Close()

'Put user code to initialize the page here

End Sub

Public Sub ChooseSite(ByVal siteID As String)

Me.useparent.ChooseSite(siteID)

End Sub

Public Property componentParent() As Master

Get

Return Me.useparent

End Get

Set(ByVal Value As Master)

Me.useparent = Value

End Set

End Property

Public Sub SiteRepeater_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.RepeaterCommandEventArgs ) Handles SiteRepeater.ItemCommand

'ChooseSite("all")

ChooseSite(CType(e.CommandArgument(), String))

End Sub

End Class

.