Single File Upload

Demo uploads land in a temporary store and are swept after 60 minutes. To keep files, handle FileUploaded — see Single File for the complete save pattern.
Single File Upload

The simplest possible AjaxUploader setup. One file at a time, auto-upload on selection, progress bar. This is the default behavior when AllowMultiple is not set or set to false. Everything else - chunked transport, drag-and-drop, cloud upload, encryption, validation - is opt-in on top of this baseline.

What you should see: the picker accepts exactly one file. Selecting a second file replaces the first in the queue.
Drag & drop files here, or paste from clipboard
Nothing saved yet - select a file; the page posts back automatically and your FileUploaded handler saves it.
<%@ Register Assembly="AjaxUploader" Namespace="AjaxUploader.Controls" TagPrefix="au" %>

<au:AjaxFileUpload ID="Uploader1" runat="server"
 ButtonText="Select a File"
 AutoUpload="true"
 AutoPostBack="true"
 OnFileUploaded="Uploader1_FileUploaded"
 ShowProgress="true" />

// Uploads land in a temp store; SAVE them in FileUploaded.
// AutoPostBack fires it automatically when the upload finishes.
protected void Uploader1_FileUploaded(object sender,
    AjaxUploader.Events.FileUploadedEventArgs e)
{
    new AjaxUploader.Services.UploadService()
        .CopyFile(e.FileGuid, "~/uploads/" + e.FileName);
}