PageAsyncTask endHandler to update the calling page

Question

I've been coerced into applying Microsoft's PageAsyncTask objects, which I am new to (before I've always used jQuery AJAX calls). I've got everything working just right except once the work is done and the endHandler is called, how do I have the calling page update its contents?

Basically my async function runs a slew of database operations and reports back to the caller with HTML regarding the results of the database run. I'd like to display these results on the calling page once the operation has completed. I have everything working except the calling page displaying the results.

Your help is appreciated.

Answer 1

Using RegisterAsyncTask makes the asp.net page lifecycle asynchronous, but from the browser's perspective, the HttpRequest is still synchronous. Essentially, when you use AsyncTasks in your asp.net page, it behaves exactly as any other asp.net page, except that during those async operations, the thread is returned to IIS so it can be used by other requests.

Therefore, your async operation shouldn't necessarily return HTML, because its caller isn't the browser; you're still within the lifecycle of the original asp.net page call. I believe your async callback can apply the DB results directly to the various controls on the page, same as you would if you hadn't implemented the operation asynchronously.