Handling AsyncFileUpload's UploadComplete event inside repeater

Question

I have a repeater that among other controls has an AsyncFileUpload and an error label all embedded inside a panel (regular, not update panel). In AFU's UploadComplete event I need to access the panel and the label; I can access the AFU itself using "sender" argument:

<asp:Repeater runat="server" ID="rpt1" ClientIDMode="Static" OnItemDataBound="rptQuestions_ItemDataBound">
    <ItemTemplate>
        < other controls>
        <asp:Panel runat="server" ID="pnlFU" clientidmode="static">
            <ajaxToolkit:AsyncFileUpload runat="server"
                ID="fuAttchedDocs" 
                clientidmode="static"
                ThrobberID="myThrobber"
                UploaderStyle="Traditional"
                OnClientUploadComplete="onClientUploadComplete"
                OnUploadedComplete="fuAttchedDocs_UploadedComplete"
                OnUploadedFileError="fuAttchedDocs_UploadedFileError" />
            <asp:Label runat="server" ID="lblError" clientidmode="static" Text="" CssClass="field-validation-error" Style="display: none" />
        </asp:Panel>
    </ItemTemplate>
</asp:Repeater>


protected void fuAttchedDocs_UploadedComplete(object sender, AsyncFileUploadEventArgs e)
{
    AsyncFileUpload fuAttchedDocs = (AsyncFileUpload)sender;

    if (fuAttchedDocs.HasFile)
    {
        // How do I access these?

        lblError.Style["display"] = "none";
        ....
        pnlFU.Style["display"] = "block";
    }
}

How do I make sure I am accessing the correct panel and label inside the repeater?

Also, when "Submit" button, located outside repeater, is clicked I am using the following to make sure all files are uploaded at once and call a js function "sendResponse()" that does a postback to deal with all the repeater items.

<button type="submit" class="btn btn-primary btn-md" onclick="javascript:document.forms[0].encoding = 'multipart/form-data';sendResponse();">Submit Response</button>

Does this seem correct? I can't test it until I figure out accessing controls inside repeater but thought I check with you if it makes sense or not.

score 1 · Accepted Answer · answered Apr 27 '18 at 17:33

I'm unfamiliar with the AsynFileUpload tool, but I can show you how, in general, to access the Label in the same panel as the sender control.

I set up an example page with roughly the same structure:

<%@ Page Language="C#" AutoEventWireup="true" CodeBehind="Test.aspx.cs" Inherits="TestRepeater.Test" %>

<!DOCTYPE html>

<html xmlns="http://www.w3.org/1999/xhtml">
<head runat="server">
    <title></title>
</head>
<body>

    <form runat="server">

        <asp:Repeater ID="repeater" runat="server">

            <ItemTemplate>

                <asp:Panel ID="ThePanel" runat="server">

                    <asp:TextBox ID="TheTextBox" OnTextChanged="TextBox_TextChanged" runat="server"></asp:TextBox>

                    <asp:Label ID="TheLabel" runat="server"></asp:Label>

                </asp:Panel>

            </ItemTemplate>

        </asp:Repeater>

        <input type="submit" />

    </form>

</body>
</html>

Here is the code-behind:

using System;
using System.Collections.Generic;
using System.Web.UI;
using System.Web.UI.WebControls;

namespace TestRepeater
{
    public partial class Test : Page
    {
        protected void Page_Load(object sender, EventArgs e)
        {
            if (!Page.IsPostBack)
            {
                // Force the creation of three repeater items.
                repeater.DataSource = new List<string>() { "", "", "" };
                repeater.DataBind();
            }
        }

        protected void TextBox_TextChanged(object sender, EventArgs e)
        {
            TextBox textBox = (TextBox)sender;

            Label label = (Label)textBox.Parent.FindControl("TheLabel");

            label.Text = "Hello, world!";
        }
    }
}

Basically, you get the Panel object containing the related controls, then find the associated label.

Here's what the example looks like in practice:

Note that updating the Label will require a postback. To update the label without a postback, you'll have to do some JavaScript trickery.

Handling AsyncFileUpload's UploadComplete event inside repeater

1 Answers1