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javascriptasp.nethtmlappendchildcreateelement

I create html div element, but it disappears immediately in ASP.NET

This is frustrating, I want to simply create new input field inside div on my aspx page when button is clicked. I use javascript function witch appends new child element(input field) to existing div. It all looks like this:

<%@ Page Language="C#" AutoEventWireup="true" CodeFile="test.aspx.cs" Inherits="Pages_test" %>

<!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 runat="server">
    <title></title>
    <script type="text/javascript">

        function clone() {
            var html = document.createElement("input");
            html.setAttribute("id", 1);
            html.setAttribute("name", "dejan");
            html.setAttribute("value", "some text");
            html.setAttribute("type", "text");
            document.getElementById("panj").appendChild(html);
        }

    </script>
</head>
    <body>
        <form id="form1" runat="server">
            <div id="panj">
                Djubrov
            </div>
            <asp:Button ID="Button1" runat="server" Text="Button" OnClientClick="clone()" />
        </form>
    </body>
</html>

Funny thing is that text element with set text value flashes for second when i click the button but it disappears afterwords. Do I missing something?

Solution

  • If you need the value from this generated text field in code behind, you would be much better off not to create it dynamically via Javascript. You could just create a normal textbox and set it to be initially invisible like so:

    <asp:TextBox ID="yourTextboxID" Visible="False" runat="server" />

    When the button is pressed, handle the event in the code behind and make the textbox visible:

    yourTextboxID.Visible = True;

    Viewstate will keep the values across postbacks.

    If each button press should create an additional textbox, you could also do this in the codebehind, i.e. use a placeholder in the ascx and then attach a new textbox to it with each button press:

    yourPlaceholderID.Controls.Add(new TextBox() { ID = "textbox1" });