Migrating From 4.x

AjaxUploader 5.0 is designed to let older Web Forms projects move forward without forcing a full rewrite on day one.

What stays familiar

What changed

  • The runtime is HTML5-based. Old Flash and Silverlight-era settings remain for compatibility, but they do not bring those runtimes back.
  • New development should prefer the AjaxUploader.* namespaces, especially AjaxFileUpload.
  • AjaxUploader.dll is the main shipping assembly for v5.
  • CuteWebUI.AjaxUploader.dll is only needed when an older project still references the old assembly name.
  • The v5 license file is ajaxuploader5.lic.
  • Local development on localhost, 127.0.0.1, or ::1 does not require license detection.
  1. Replace the old binaries with the latest AjaxUploader.dll.
  2. Keep your CuteWebUI markup and code-behind in place first.
  3. Register the ajaxupload.axd handler and make sure uploads work end to end.
  4. Verify your old server-side events and attachment flows on a real postback.
  5. Migrate individual pages to AjaxUploader.Controls.* only when you want cleaner v5-native markup.

Practical assembly guidance

For a normal v5 Web Forms app:

  • Use AjaxUploader.dll
  • Register AjaxUploader.Controls

For an upgraded 4.x app that still has old assembly references:

  • Use AjaxUploader.dll
  • Optionally keep CuteWebUI.AjaxUploader.dll only if the application still depends on the old assembly identity

Typical upgrade pattern

Start by keeping the old control:

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

<CuteWebUI:Uploader ID="Uploader1" runat="server"
    InsertText="Select files"
    MultipleFilesUpload="true"
    OnFileUploaded="Uploader1_FileUploaded" />

Then move to the native v5 control later if you want:

<%@ Register Assembly="AjaxUploader" Namespace="AjaxUploader.Controls" TagPrefix="au" %>

<au:AjaxFileUpload ID="Uploader1" runat="server"
    ButtonText="Select files"
    Multiple="true"
    OnFileUploaded="Uploader1_FileUploaded" />

Server-side events fire automatically

This is the behaviour upgraded pages depend on most, so it is worth stating plainly: the legacy Uploader and UploadAttachments controls post back automatically when the upload batch finishes, exactly as they did in 4.x. Your FileUploaded, UploadCompleted, and AttachmentAdded handlers run with no submit button on the page and no extra code - select a file, and the server-side event fires.

If you are wiring up a page from scratch with the modern AjaxFileUpload control instead, that automatic postback is opt-in there: set AutoPostBack="true". The legacy wrappers turn it on for you so old markup keeps working unchanged. (An explicit AutoPostBack="false" in your markup is still honoured if a normal submit button drives the form.)

Compatibility expectation

The goal of the CuteWebUI layer is upgrade continuity:

  • old markup should keep compiling
  • old code-behind patterns should keep working
  • server-side events (FileUploaded, UploadCompleted, AttachmentAdded) should keep firing automatically after upload
  • HTML5 upload behavior should be better than the old runtime

The goal is not to recreate the old browser plugins or every legacy visual behavior exactly.

Where to go next