Accessing the value of a dynamically added Control inside Update panel

Question

I have a page which contains an update panel and inside it, we have a placeHolder which will be populated with a textbox when button1 is pressed.

Now I neeed to access the value entered in the textbox when the user click Button2. I am struggling to find a simple solution to this problem.

Please find the below code snippet.

<form id="form1" runat="server">
<asp:ScriptManager ID="ScriptManager1" runat="server">
</asp:ScriptManager>
<div>
    <asp:UpdatePanel ID="UpdatePanel1" runat="server">
        <ContentTemplate>
            <asp:PlaceHolder ID="wplcHolder" runat="server"></asp:PlaceHolder>
        </ContentTemplate>
    </asp:UpdatePanel>
    <asp:Button ID="Button1" runat="server" Text="Button" onclick="Button1_Click" />
    <asp:Button ID="Button2" runat="server" Text="Button" onclick="Button2_Click" />
</div>
</form>

protected void Button1_Click(object sender, EventArgs e)
{
    TextBox _txt = new TextBox();
    wplcHolder.Controls.Add(_txt);
}

Thanks, Chandru

Answer 1

I suggest you to give an ID to the textbox before adding it to the placeholder, for example let's say you give: yourTextBoxID

after that, in theory you could do this from your Button2_Click event:

var myTextBox = (wplcHolder.FindControl("yourTextBoxID") as TextBox);

this would work but only if you add the yourTextBoxID control all the times in the Page_Init because if you only do it from Button1_Click when a new page life cycle is triggered by clicking on Button2 most likely the textbox won't be there.

all to be tested and verified of course ;-)