dynamically adding controls with events (but events are not firing)

Discussion in 'ASP .Net' started by SevDer, Nov 13, 2007.

  1. SevDer

    SevDer Guest

    Hi,

    I have a very simple page where I have a dynamically generated control
    (panel) with child controls, but the problem is the dynamically added
    control has events and they are not fired which I expect to have a recursive
    page generations.

    Here is my aspx.
    ------------------------------------------------------------
    <body>
    <form id="form1" runat="server">
    <div>
    <asp:panel ID="Panel1" runat="server" Height="54px" Width="140px">
    <asp:Label ID="lTitle" runat="server" Text="My Title"></asp:Label><br />
    <asp:Button ID="bPopulate" runat="server" Text="Populate Me"
    OnClick="PopulateChildren" CommandArgument="1" /></asp:panel>
    </div>
    </form>
    </body>

    And here is the code behind to generate the dynamic content.
    ------------------------------------------------------------
    public partial class _Default : System.Web.UI.Page
    {
    protected void Page_Load(object sender, EventArgs e)
    {
    ArrayList dynamicContent;
    if (Session["MyItems"] != null)
    {
    dynamicContent = Session["MyItems"] as ArrayList;
    foreach (Panel toAddPanel in dynamicContent)
    {
    Page.Form.Controls.Add(toAddPanel);
    }
    }

    }

    protected void PopulateChildren(object sender, EventArgs e)
    {
    Button parentButton = (Button)sender;

    Panel childPanel = new Panel();
    childPanel.EnableViewState = true;

    Label childLabel = new Label();
    childLabel.Text = "Child of " +
    ((Label)((Panel)(parentButton).Parent).Controls[1]).Text;
    childLabel.EnableViewState = true;

    Literal childLiteral = new Literal();
    childLiteral.Text = "<br>";
    childLiteral.EnableViewState = true;

    Button childButton = new Button();
    childButton.Text = "Child of " + ((Button)sender).Text;
    childButton.Click += new EventHandler(PopulateChildren);
    childButton.EnableViewState = true;

    childPanel.ID = "p" + (int.Parse(parentButton.CommandArgument) +
    1).ToString();
    childLabel.ID = "cl" + (int.Parse(parentButton.CommandArgument) +
    1).ToString();
    childLiteral.ID = "clt" + (int.Parse(parentButton.CommandArgument) +
    1).ToString();
    childButton.ID = "cb" + (int.Parse(parentButton.CommandArgument) +
    1).ToString();

    childPanel.Controls.Add(childLabel);
    childPanel.Controls.Add(childLiteral);
    childPanel.Controls.Add(childButton);

    ArrayList dynamicContent;
    if (Session["MyItems"] != null)
    dynamicContent = Session["MyItems"] as ArrayList;
    else
    dynamicContent = new ArrayList();
    dynamicContent.Add(childPanel);
    Session["MyItems"] = dynamicContent;


    Page.Form.Controls.Add(childPanel);


    }
    }

    Here I am not insisting on the part that I have in Page_Load but some way I
    need to persist the controls in the page and have the events from those
    fired.

    Can anyone guide me please?

    SevDer
    http://www.sevder.com
     
    SevDer, Nov 13, 2007
    #1

    1. Advertisements

  2. SevDer

    bruce barker Guest

    you can not store the dynamic controls in session. they belong to the
    previous page, and becuase they hold a delegat, those pages object are
    held, and events if fired, run in the old pages. this also leads to
    great memory leaks.

    also as every page request is a new class instance, you need to attach
    event handlers.

    you should store info in session that allows you to recreate the dynamic
    content. you shouls also recreate at oninit, not pageload.

    -- bruce (sqlwork.com)
     
    bruce barker, Nov 13, 2007
    #2

    1. Advertisements

  3. SevDer

    Walter Wang [MSFT] Guest

    Hi SevDer,

    In addition to Bruce's reply, you may find following KBs useful:

    #HOW TO: Dynamically Create Controls in ASP.NET by Using Visual C# .NET
    http://support.microsoft.com/kb/317794

    #HOW TO: Dynamically Create Controls in ASP.NET with Visual Basic .NET
    http://support.microsoft.com/kb/317515


    Regards,
    Walter Wang (, remove 'online.')
    Microsoft Online Community Support

    ==================================================
    When responding to posts, please "Reply to Group" via your newsreader so
    that others may learn and benefit from your issue.
    ==================================================

    This posting is provided "AS IS" with no warranties, and confers no rights.
     
    Walter Wang [MSFT], Nov 13, 2007
    #3

    1. Advertisements

Ask a Question

Want to reply to this thread or ask your own question?

You'll need to choose a username for the site, which only take a couple of moments (here). After that, you can post your question and our members will help you out.
Similar Threads

  1. Dynamically loaded user control events not firing on first click

  2. Adding button at runtime: Events not firing

  3. UserControl Events Not Firing with Dynamically Created Button Control

  4. ButtonColumn not firing after dynamically adding a row to my datagrid.

  5. Event not firing. Adding controls dynamically to UserControl

  6. Adding Button at runtime: Events not firing

  7. Child controls in Composite Controls not firing events

  8. Dynamically Created Controls Not Firing Events

Loading...