Showing posts with label linkbuttons. Show all posts
Showing posts with label linkbuttons. Show all posts

Wednesday, March 28, 2012

Dynamic controls and Updatepanel

Hi,

First time poster here. (waves)

Here is my problem: Dynamically created LinkButtons within an Updatepanel don't seem to fire their Commands.
I have a few LinkButtons that are dynamically created within an UpdatePanel based on the contents of a TextBox. Everything renders as it should, only when I click on one of the LinkButtons, nothing happens. When I Debug, it the function the LinkButtons refer to (trough Command) never fires up. I suspect that this has something to do with the fact that CommandEventHandler is never actually registered because of the partial update. Is this correct? What are my options in this situation?

hello.

can you show us the code?


This is the code that is being used to generate the buttons:
foreach (XmlNode rowin rows){ LinkButton klantLink =new LinkButton(); klantLink.Text = row["NAME"].InnerText +", " + row["FIRSTNAME"].InnerText; klantLink.CommandArgument = row["K_CONTACT"].InnerText; klantLink.Command +=new CommandEventHandler(gezochteKlant_Click); searchDiv.Controls.Add(klantLink); searchDiv.Controls.Add(new LiteralControl("<br />") );}
searchDiv.Visible = true;
searchPanel.Update();
And this is the location in the html where the content is added:
<atlas:UpdatePanel ID="searchPanel" runat="server" Mode="Conditional"> <ContentTemplate> <div runat="server" id="searchDiv" visible="false"> </div> </ContentTemplate></atlas:UpdatePanel>

hello again.

question: where are you adding the controls, ie, in which event?


They are added trough the OnTextChanged of a textbox.

hello.

hum, not sure about what's happening.

i've built a small sample that adds a button during the load event and this works ok:

<%@. Page Language="C#" %>

<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Transitional//EN" "http://www.w3.org/TR/xhtml1/DTD/xhtml1-transitional.dtd">

<script runat="server">
protected override void OnLoad(EventArgs e)
{
base.OnLoad(e);

LinkButton klantLink = new LinkButton();
klantLink.Text = "hello";
klantLink.CommandArgument = "test";
klantLink.Command += new CommandEventHandler(gezochteKlant_Click);

searchDiv.Controls.Add(klantLink);
searchDiv.Controls.Add(new LiteralControl("<br />"));

}

void gezochteKlant_Click(object sender, EventArgs args)
{
txt.Text = DateTime.Now.ToString();
}
</script>

<html xmlns="http://www.w3.org/1999/xhtml" >
<head runat="server">
<title>Untitled Page</title>
</head>
<body>
<form id="form1" runat="server">
<div>
<atlas:ScriptManager runat="server" ID="manager" EnablePartialRendering="true" />

<atlas:UpdatePanel runat="server" id="panel">
<ContentTemplate>
<div runat="server" id="searchDiv" />
<asp:TextBox runat="server" id="txt" />
</ContentTemplate>
</atlas:UpdatePanel>
<hr />
<%= DateTime.Now.ToString() %>
</div>
</form>
</body>
</html>

maybe the problem is that you're only creating the button during the textchanged event; a click will fire another postback, but you won't the buttons won't be created since the text didn't change and this will not fire your event.


Thanks for the reply. I think the problem is that I create the controls directly in the function linked to the ontextchanged event.

hello.

that's what i was trynig to say. since you add them on the textchanged event, you must also add them on future postbacks or else the button will not exist. so, what i suggest is adding some sort of flag that will let you add the buttons during the load event of a postback operation.


Hi,

I am very badly stuck up at something.

I am also dynamically loading my user control in the Update panel. My User Control act as a ModalPopUp Extender. So what i am doing is , on the click on the button on my page I am showing a Modal PopUp which is a User Control with some buttons and a grid. Which is being loaded on some values passed from the Page. So what I have done is I am adding Dynamically that user Control on the Click event of the button on my Page.But when I click any button my User Control , the event associated with that button does not get fired. It just unloades the usecontrol and event related to the buttons on the User control are getting fired.. Please help and look into this matter..

The Code:

protectedvoid btnAddContent_Click(object sender,EventArgs e)

{

//AddContent1 is my User Control with ProposalID and SectionID are the Properties.. Place Holder is on my Page where I am placing my control.

AddContent

AddContent1 = (AddContent)Page.LoadControl("AddContent.ascx");

AddContent1.ProposalID = 44;

AddContent1.SectionID = 1;

PlaceHolderTest.Controls.Add(AddContent1);

Label lblAdd = (Label)(AddContent1.FindControl("lblAdd"));

lblAdd.Text =

"Add Content";Label lblSecQues = (Label)(AddContent1.FindControl("lblSecQues"));

lblSecQues.Text =

"Section:";

mpeAddContent.Show();

}

Thanks in Avance

Abhishek

Dynamic controls and problem with UpdateProgress

I dynamically create several LinkButtons, and attach enenthandler for command event, and assign it for triggering Updatepanel. It works, but UpdateProgress doesn't show. I tried to add static button and assign it to updatepanel for triggering, and in this case updateprogress works, so i guess that's everything ok with ajax.

This is code in aspx:

1<asp:PlaceHolder ID="phMenu" runat="server"></asp:PlaceHolder>2<asp:UpdateProgress ID="UpdateProgress1" AssociatedUpdatePanelID="UpdatePanel1" runat="server" DisplayAfter="10">3 <ProgressTemplate>4 <span style="color: #ff0066">5 loading... </span>6</ProgressTemplate>7</asp:UpdateProgress>89<asp:UpdatePanel ID="UpdatePanel1" runat="server" >10<ContentTemplate>11<table width="100%" cellpadding=2 cellspacing=0 border=0>12 <asp:Repeater ID="rptFeeds" runat="server" EnableViewState=false>13 <ItemTemplate>14 <tr>15 <td>16 ... some data from db...17 </td>18 </tr>19 </ItemTemplate>20 </asp:Repeater>21 </table></ContentTemplate>22</asp:UpdatePanel>

code-behind in void OnInit:

1foreach (Category catin list)2{3 Panel pnl =new Panel();4 pnl.ID ="menu_" + cat.Id.ToString() ;5 pnl.CssClass ="menu_item";67 LinkButton lb =new LinkButton();8 lb.CommandArgument = cat.Id.ToString();9 lb.Command +=new CommandEventHandler(Clicked);10 lb.ID="trigger_"+cat.Id.ToString();11 lb.Text = cat.Name;12 lb.CssClass ="menu_a";1314 AsyncPostBackTrigger trigger =new AsyncPostBackTrigger();15 trigger.ControlID ="trigger_" + cat.Id.ToString();16 trigger.EventName ="Command";17 UpdatePanel1.Triggers.Add(trigger);1819 pnl.Controls.Add(lb);20 phMenu.Controls.Add(pnl);21}2223protected void Clicked(object sender, CommandEventArgs e)24{25 ChangeCat(Convert.ToInt32(e.CommandArgument));26}

Can you see why UpdateProgess doesn't work?

Hi,hudo

I think it's a normal issue.

You can set the clientclick property of theDynamic controls to show the UpdateProgess.

Thanks


The problem is that the control you want to trigger the UpdateProgress control is not inside the UpdatePanel.

See my post here:http://smarx.com/posts/why-the-updateprogress-wont-display.aspx for an explanation of why that doesn't work.

Monday, March 26, 2012

Dyanmically created linkbuttons, within UpdatePanel, is not working

Hello Folks,

I am updating a placeholder, to create some form controls, from my code behind.

I am successful. Now, I want to create a linkbutton, next to each form control i create, that when clicked on, go to the same generic event and read the control's ID (passed by the linkbutton somehow) and then I will do the logic to remove the control from the placeholder. Right now it creates the linkbuttons, but to ensure i don't have duplicate ID's, I add a unique int.tostring on the end of the ID of the linkbuttons. And I added the handler that should send all clicks, from all the linkbuttons to the same event. But I put a breakpoint in that event and when I click any of the linkbuttons, it just refreshes and no change to the page and the breakpoint in the event is never reached. Please let me know if you have any ideas, questions.. a portion of my code, with notes, below...

I am able to create all form elements except buttons, link buttons, etc.

I think the link button creation should be as simple as:

victorylinkBTN.ID ="victorylinkBTN" & VictoryReplicantCount.ToString

AddHandler victorylinkBTN.Click,AddressOf victorylinkBTN_Click

DCP.Controls.Add(victorylinkBTN)

victorylinkBTN.Text ="Del"

Dim vicEventAsNew System.EventArgs()

Is that right? It does create the linkbuttons, but the click fails. It submits, but nothing happens, it just refreshes with nothing changed, and doesn't land on my breakpoint, in the sub below.

Sub victorylinkBTN_Click(ByVal senderAsObject,ByVal eAs System.EventArgs)

Dim linkbutAs LinkButton =CType(sender, LinkButton)

Dim linkbutIDAsString = linkbut.ID.ToString

'do more work……

EndSub

If you have any idea what I am doing wrong, please let me know.

Also, if you have experience with update panels, if I make the update panel conditional, then how would I set each of these linkbuttons to have trigger rights to the related update panel?

Again, thanks for any help ...

Folks,

I have found a cheesy way to do this, by adding javascript on each linkButton created that inserts the linkButton ID into a hidden field's value on the page and then on that linkButton submit, in pageLoad, I read the value of the hidden field to decide to perform the action.

This works, and would take some serious time to explain. Please feel free to email me via the forum contact ability, if you want details.

I am leaving this open, hoping someone in the asp.net team will have a better solution.


Since you dynamically add thelink buttons, you should add it to the PlaceHolder in the Page_Load event every time instead of adding it just the page first load. Because when you only add it the first time the page load, after post back, thelink buttonswill disappear. And itdoesn't land on your breakpoint invictorylinkBTN_Click,There is non victorylinkBTN when your postback.

Try this:

publicpartialclassDefault2 : System.Web.UI.Page

{

protectedvoid Page_Load(object sender,EventArgs e)

{

AddControl(PlaceHolder_ContentRight,"~/WebUserControl.ascx",true);

}

privatevoid AddControl(PlaceHolder PlaceHolder,string ControlPath,bool Clear)

{

Control Control_ToAdd;

Control_ToAdd = LoadControl(ControlPath);

if (Clear)

{

PlaceHolder.Controls.Clear();

}

PlaceHolder.Controls.Add(Control_ToAdd);

}

}

If this help you,don't forget mark it as a answer.Thanks!

Best Regards

Jin-Yu Yin