Go Premium for a chance to win a PS4. Enter to Win

x
?
Solved

How to fire ItemCommand Event on programatically added Datalist

Posted on 2009-04-12
6
Medium Priority
?
1,177 Views
Last Modified: 2013-12-17
Hi,
I have a user control with a datalist and a textbox. I programatically added the user control in my page_load. The idea is when i click on a button in the datalist, the textbox will reflect the id on the selected datalist item.

The problem is, i can't seem to get the itemcommand events to be fired. Please advise.
.asc.vb
========
 
Partial Class UserCtrl
    Inherits System.Web.UI.UserControl
 
    Private _username As String
    Public Event getItemOnCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs)
 
    Protected Sub Datalist1_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs)
 
        If e.CommandName = "getID" Then
            TextBox1.Text = "You have clicked on the datalist button"
        End If
 
        RaiseEvent getItemOnCommand(Me, e)
 
    End Sub
 
 
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Load
 
        If Not Page.IsPostBack Then
            'Nothing fancy, just populating the datalist with rows.
            Dim dt As New DataTable
            Dim dr As DataRow
            Dim dc As DataColumn
 
            dc = New DataColumn
            dc.ColumnName = "id"
            dt.Columns.Add(dc)
            dc = New DataColumn
            dc.ColumnName = "name"
            dt.Columns.Add(dc)
 
            dr = dt.NewRow
            dr("id") = 1
            dr("name") = "andy"
            dt.Rows.Add(dr)
 
            dr = dt.NewRow
            dr("id") = 2
            dr("name") = "ethan"
            dt.Rows.Add(dr)
 
            dr = dt.NewRow
            dr("id") = 3
            dr("name") = "Matt"
            dt.Rows.Add(dr)
 
            Datalist1.DataSource = dt
            Datalist1.DataBind()
        End If
 
    End Sub
 
 
.asc
============
<%@ Control Language="VB" AutoEventWireup="true" CodeFile="UserCtrl.ascx.vb" Inherits="UserCtrl" %>
 
<asp:TextBox ID="TextBox1" runat="server"></asp:TextBox>
 
<asp:DataList ID="Datalist1" runat="server" 
        DataKeyField="id" 
        RepeatColumns = "3">
<HeaderTemplate>
    <strong>Selection Table</strong>
</HeaderTemplate>
<ItemTemplate>
    ID: <%#Eval("id")%>
    <br />
    Name: <%#Eval("name")%>
    <br />
    <asp:Button runat="server" CommandName="getID" Text="Get ID" CommandArgument='<%#Eval("id")%>' />
    <br /><br />
</ItemTemplate>
</asp:DataList>
 
.aspx.vb
============
 
Imports System.Data
Imports System.Collections.Generic
 
Partial Class Default4
    Inherits System.Web.UI.Page
 
    Private Sub UserControlDatalist_getItemCommand(ByVal sender As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs)
 
        MsgBox("this is user control")
        Dim dummy As UserCtrl = sender
        Dim txt As TextBox = dummy.FindControl("TextBox1")
 
        Response.Write(txt.Text)
 
    End Sub
 
    Protected Sub Page_Load(ByVal sender As Object, ByVal e As System.EventArgs) Handles Me.Init
 
        Dim userCtrl As UserCtrl = LoadControl("UserCtrl.ascx")
 
        PlaceHolder1.Controls.Add(userCtrl)
 
        AddHandler userCtrl.getItemOnCommand, AddressOf UserControlDatalist_getItemCommand
 
    End Sub
 
 
End Class
 
.aspx
=======
<%@ Page Language="VB" AutoEventWireup="false" CodeFile="Default4.aspx.vb" Inherits="Default4" %>
<%@ Register TagPrefix="My" TagName="UserCtrl" Src="UserCtrl.ascx" %> 
 
<!--Now we can access the UserInfoBoxControl class like if it were a regular class, 
which also means that we can typecast the UserControl returned by the LoadControl method to this type-->
<%@ Reference Control="UserCtrl.ascx" %>
 
<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">
 
<html xmlns="http://www.w3.org/1999/xhtml">
<head id="Head1" runat="server">
    <title></title>
</head>
<body>
    <form id="form1" runat="server">
    <div>
        <asp:PlaceHolder runat="server" ID="ph1" /><br />
        <asp:PlaceHolder runat="server" ID="ph2" />
        <asp:Button runat="server" ID="btnAddBtn" Text="Add Button" CommandName="Button" /> 
        <asp:Button runat="server" ID="btnAddText" Text="Add Text" CommandName="TextBox" />
        <asp:Button runat="server" ID="btnAddDataList" Text="Add DataList" CommandName="DataList" />
    </div>
    <div>
    
    <asp:PlaceHolder ID="PlaceHolder1" runat="server"></asp:PlaceHolder>
    
    </div>
    </form>
</body>
</html>

Open in new window

0
Comment
Question by:tangteng78
  • 3
  • 3
6 Comments
 
LVL 11

Expert Comment

by:Anurag Agarwal
ID: 24128252
Have you registered the Datalist1.ItemCommand on UserCtrl.ascx to call your function Datalist1_ItemCommand??
 
Anurag
0
 

Author Comment

by:tangteng78
ID: 24128322
From the code snippet attached i did this:
     Protected Sub Datalist1_ItemCommand(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs)

        If e.CommandName = "getID" Then
            TextBox1.Text = "You have clicked on the datalist button"
        End If

        RaiseEvent getItemOnCommand(Me, e)

    End Sub

Not sure if that's what you meant by register? If it's not, can you share with me how to register the events?
 
0
 
LVL 11

Expert Comment

by:Anurag Agarwal
ID: 24128840
On control UserCtrl.ascx you have to register the ItemCommand like
AddHandler userCtrl.ItemCommand, AddressOf Datalist1_ItemCommand
check whether you have already done that if not then do it.
 
Anurag
0
Free Backup Tool for VMware and Hyper-V

Restore full virtual machine or individual guest files from 19 common file systems directly from the backup file. Schedule VM backups with PowerShell scripts. Set desired time, lean back and let the script to notify you via email upon completion.  

 

Author Comment

by:tangteng78
ID: 24129205
Added in in the page_load in the ascx.vb. Stil the same, not working.

PS: I created a separate user control and replace the datalist with just a button. And it works. Seems to me that the datalist just not working with the same  button implementation

Please advise.


0
 

Author Comment

by:tangteng78
ID: 24129421
Well, i finally able to get it to work. I added in the "Handles Datalist1.ItemCommand" to the Sub Datalist1_ItemCommand in the asc.vb.

But my question is, if i do the same on the Button1_click event, the button will be fired twice. I have to commented out the "Handles Button1.Click" for it to work correctly (fire only 1 time).

Any explaination?

    Protected Sub Datalist1_ItemCommand1(ByVal source As Object, ByVal e As System.Web.UI.WebControls.DataListCommandEventArgs) Handles Datalist1.ItemCommand
        _username = e.CommandName.ToString
        If e.CommandName = "getID" Then
            'MsgBox(e.CommandArgument.ToString)
            TextBox1.Text = "You have clicked on the datalist button" + e.CommandArgument.ToString
        End If

        RaiseEvent getItemOnCommand(Me, e)
    End Sub

    Protected Sub Button1_Click(ByVal sender As Object, ByVal e As System.EventArgs) ' Handles Button1.Click
        _username = TextBox1.Text
        RaiseEvent getClick(Me, e)
    End Sub
0
 
LVL 11

Accepted Solution

by:
Anurag Agarwal earned 1500 total points
ID: 24129788
check your designer.cs file one handler should already added in that, because of that this event is fired twice.
 
Anurag
0

Featured Post

NEW Veeam Agent for Microsoft Windows

Backup and recover physical and cloud-based servers and workstations, as well as endpoint devices that belong to remote users. Avoid downtime and data loss quickly and easily for Windows-based physical or public cloud-based workloads!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Today I had a very interesting conundrum that had to get solved quickly. Needless to say, it wasn't resolved quickly because when we needed it we were very rushed, but as soon as the conference call was over and I took a step back I saw the correct …
If you need to start windows update installation remotely or as a scheduled task you will find this very helpful.
This Micro Tutorial will teach you how to add a cinematic look to any film or video out there. There are very few simple steps that you will follow to do so. This will be demonstrated using Adobe Premiere Pro CS6.
Are you ready to place your question in front of subject-matter experts for more timely responses? With the release of Priority Question, Premium Members, Team Accounts and Qualified Experts can now identify the emergent level of their issue, signal…
Suggested Courses

885 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question