Legacy UploadAttachments

UploadAttachments is the compatibility control for form-style attachment lists.

Use it when an older page expects:

  • an attachment table UI
  • the Items collection
  • AttachmentItem event hooks
  • optional custom attachment providers

Typical markup

<%@ Register Assembly="AjaxUploader" Namespace="CuteWebUI" TagPrefix="CuteWebUI" %>

<CuteWebUI:UploadAttachments ID="Attachments1" runat="server"
    InsertText="Upload multiple files"
    MultipleFilesUpload="true"
    ShowQueueTable="true"
    ShowTableHeader="true"
    ShowRemoveButtons="true"
    OnFileUploaded="Attachments1_FileUploaded"
    OnAttachmentAdded="Attachments1_AttachmentAdded"
    OnAttachmentRemoveClicked="Attachments1_AttachmentRemoveClicked">
    <ValidateOption AllowedFileExtensions="pdf,doc,docx,xls,xlsx,zip" MaxSizeKB="20480" />
</CuteWebUI:UploadAttachments>

Typical code-behind

protected void Attachments1_FileUploaded(object sender, CuteWebUI.UploaderEventArgs e)
{
    litLog.Text += "<div>Uploaded: " + Server.HtmlEncode(e.FileName) + "</div>";
}

protected void Attachments1_AttachmentAdded(object sender, CuteWebUI.AttachmentItemEventArgs e)
{
    e.Item.SetCustomData("category", "invoice");
}

protected void Attachments1_AttachmentRemoveClicked(object sender, CuteWebUI.AttachmentItemEventArgs e)
{
    e.Behavior = CuteWebUI.AttachmentItemBehavior.AutoRemove;
}

Working with the collection

foreach (CuteWebUI.AttachmentItem item in Attachments1.Items)
{
    if (item.ShouldSave)
    {
        var path = Server.MapPath("~/App_Data/Attachments/" + item.FileName);
        using (var input = item.OpenStream())
        using (var output = System.IO.File.Create(path))
        {
            input.CopyTo(output);
        }
    }
}

Automatic postback (4.x parity)

As in 4.x, UploadAttachments posts back automatically when the upload batch finishes. AttachmentAdded, AttachmentCreated, and FileUploaded fire on the server with no submit button, the item enters the Items collection, and the attachment row renders - all with no extra code. This is on by default; set AutoPostBack="false" if a normal submit button already drives the form and you would rather process the attachments then.

Custom provider scenarios

CustomProvider is for pages that mix AjaxUploader temp files with records that already exist somewhere else.

The provider contract lives at IAttachmentProvider.