Dynamically loading ascx page and having events fire

[Shawn Meyer]

Im sure this has been discussed here before but I have had no luck finding
an answer.

I am trying to create a simple web app, with a navigation on one side that
will load up pages on the other. The nav side is a custom control, that has
an event that fires upon click, and then sets a selectedindex. I am using
the selected index to determine what ascx page to load up. I created a
"LoadControl" function to load the ascx page and add it to the placeholder
controls. This function gets called when the selectedindexchaged event
fires (which is mapped to the nav control), and a viewstate variable gets
set. The PostBack function checks for this variable and if there, calls the
loadcontrol again.

** The ascx pages that I load have post back items on them, such as a
textboxs and submit button.
The nav events fire, which loads the ascx correctly, however the first time
I hit submit button, the button click event (on the loaded ascx page) does
not fire. Every time after that the event fires properly.

From what I have read, when you load an ascx after the after the pageload
has executed (ie. due to a event ) your events on the loaded page will not
work properly because they were not loaded during pageload. And after the
second click it worked because of my call to LoadControl in the postback.

Some people have suggested to load all of your pages, and toggle visibility,
but this really isn't an option since I plan on having a large number of
pages on the site.

Is there any way to make this work? Attached is the code snips.

-- Page load
<snip>
if ( isPostBack )

{

if (ViewState["Control1"] != null )

{

LoadControl();

}

}

<snip>

private System.Web.UI.Control home_control;

private void LoadControl()

{

switch (FooterPanelBar.SelectedIndex)

{

case 0:

home_control = LoadControl("a.ascx");

PlaceHolder_Body.Controls.Add(home_control);

break;

case 1:

home_control = LoadControl("b.ascx");

PlaceHolder_Body.Controls.Add(home_control);

break;

}

}

private void FooterPanelBar_SelectedIndexChanged(object sender, EventArgs e)

{

PlaceHolder_Body.Controls.Clear(); // clear out the loaded one to
perform switch to new ascx

LoadControl();

ViewState["Control1"] = "Control1";

}

Thanks, Shawn Meyer

[Alessandro Zifiglio]

hi Shawn,
You need to supply an id to your control. This is because the second time
you load the control you are loading it in a different location.
In your LoadControl method, right after you add your control to the
placeholder supply an id and the problem is solved, like :

switch (FooterPanelBar.SelectedIndex)

{

case 0:

home_control = LoadControl("a.ascx");

PlaceHolder_Body.Controls.Add(home_control);
home_control.id = "a";

break;

case 1:

home_control = LoadControl("b.ascx");

PlaceHolder_Body.Controls.Add(home_control);
home_control.id = "b";

break;

}

"Shawn Meyer" <sme...@interelate.com> wrote in message
news:uwUUS155...@TK2MSFTNGP11.phx.gbl...

> Im sure this has been discussed here before but I have had no luck finding
> an answer.
>
> I am trying to create a simple web app, with a navigation on one side that
> will load up pages on the other. The nav side is a custom control, that
has
> an event that fires upon click, and then sets a selectedindex. I am using
> the selected index to determine what ascx page to load up. I created a
> "LoadControl" function to load the ascx page and add it to the placeholder
> controls. This function gets called when the selectedindexchaged event
> fires (which is mapped to the nav control), and a viewstate variable gets
> set. The PostBack function checks for this variable and if there, calls
the
> loadcontrol again.
>
> ** The ascx pages that I load have post back items on them, such as a
> textboxs and submit button.
> The nav events fire, which loads the ascx correctly, however the first
time
> I hit submit button, the button click event (on the loaded ascx page)

doesswitch (FooterPanelBar.SelectedIndex)

[Alessandro Zifiglio]

if its not clear what i mean by a different location, i mean one time you
add it when the selected index changes, and another time you add it in
page_load --supplying an id is the way to resolve.
"Alessandro Zifiglio" <alessandr...@NO-SPAM-hotmail.com> wrote in
message news:O8RSb.1985$HO2....@news.edisontel.com...

[Shawn Meyer]

This didnt work. The events on the loaded ascx will not fire, on the first
postback. After the first postback everything works as planned. Any
thoughts?

"Alessandro Zifiglio" <alessandr...@NO-SPAM-hotmail.com> wrote in

message news:QhRSb.1993$HO2....@news.edisontel.com...

[Alessandro Zifiglio]

This works perfectly. I had reconstructed your exact same scenario before
posting. With the only difference that i were using a radiobuttonlist
control and loading controls in its selectedIndex changed event.
Also note that initially when not supplying an explicit id I experienced the
same problem you were facing. The fix is to supply an ID --this is because
you are loading your controls at different locations like i stated.

Private Sub Page_Load(ByVal sender As System.Object, ByVal e As
System.EventArgs) Handles MyBase.Load
If IsPostBack Then
If Not viewstate("controls") Is Nothing Then
LoadControls()
End If
End If
End Sub

Private Sub LoadControls()
Dim control1 As Control
Select Case RadioButtonList1.SelectedIndex
Case 0
control1 = LoadControl("webUserControl1.ascx")
PlaceHolder1.Controls.Add(control1)
control1.ID = "Mycontrol1"
viewstate("controls") = 0
Case 1
control1 = LoadControl("webUserControl2.ascx")
PlaceHolder1.Controls.Add(control1)
control1.ID = "Mycontrol2"
viewstate("controls") = 1
End Select
End Sub

Private Sub RadioButtonList1_SelectedIndexChanged(ByVal sender As
Object, ByVal e As System.EventArgs) Handles
RadioButtonList1.SelectedIndexChanged
Dim control1 As Control
PlaceHolder1.Controls.Clear()
LoadControls()
End Sub

"Shawn Meyer" <m...@me.com> wrote in message
news:estABcb...@tk2msftngp13.phx.gbl...

[Alessandro Zifiglio]

The Html view is :

<body MS_POSITIONING="GridLayout">
<form id="Form1" method="post" runat="server">
<asp:radiobuttonlist id="RadioButtonList1" style="Z-INDEX: 103; LEFT:
281px; POSITION: absolute; TOP: 270px" runat="server" AutoPostBack="True">
<asp:ListItem Value="control1">control1</asp:ListItem>
<asp:ListItem Value="control2">control2</asp:ListItem>
</asp:radiobuttonlist><asp:placeholder id="PlaceHolder1"
runat="server"></asp:placeholder>
</form>

Give it another try. It works :)

"Shawn Meyer" <m...@me.com> wrote in message
news:estABcb...@tk2msftngp13.phx.gbl...

[Alessandro Zifiglio]

and to complete here is the code i used for the webUsercontrols. As you can
see both have a click event that postsback.

webUserControl1.ascx :

<%@ Control Language="vb" AutoEventWireup="false"
Codebehind="WebUserControl2.ascx.vb"
Inherits="WebApplication1.WebUserControl2"
TargetSchema="http://schemas.microsoft.com/intellisense/ie5" %>
<h1 style="BACKGROUND-COLOR: #ffcc66">this is Control2
<asp:Button id="Button1" Text="control 2" runat="server"></asp:Button></h1>

webcontrol1.vb :
Private Sub Button1_Click(ByVal sender As Object, ByVal e As
System.EventArgs) Handles Button1.Click
Response.Write("<h2>control2 fired</h2>")
End Sub

I have the same code for webUsercontrol2

"Alessandro Zifiglio" <alessandr...@NO-SPAM-hotmail.com> wrote in

message news:%RxTb.2727$HO2...@news.edisontel.com...

[Shawn Meyer]

I was trying to everything to fix the problem, and accidentally changed some
important code. After fixing that problem, adding the ID worked
beautifully, thanks alot. Sorry about the confusion.

"Alessandro Zifiglio" <alessandr...@NO-SPAM-hotmail.com> wrote in

message news:m9yTb.2733$HO2...@news.edisontel.com...

[Alessandro Zifiglio]

Great. Its what i thought myself. Glad you got it working now :)

"Shawn Meyer" <sme...@interelate.com> wrote in message

news:%23a5yo3m...@TK2MSFTNGP10.phx.gbl...

[Earl Teigrob]

Thanks, Alessando, this solved the same problem I have been trying to
resolve for may hours. Yeah!!!
(what in the H would a programmer do without newsgroups???)

Earl

"Alessandro Zifiglio" <alessandr...@NO-SPAM-hotmail.com> wrote in
message news:O8RSb.1985$HO2....@news.edisontel.com...

[Alessandro Zifiglio]

lol Earl, I'm glad that helped you too :)
Your right about the news groups. I'm addicted ;P
"Earl Teigrob" <earl...@hotmail.com> wrote in message
news:%23BHppWz...@TK2MSFTNGP12.phx.gbl...