CODEWITHSUNDEEP
asp.netwebformsasync-awaitasp.net-ajax
Andre DeMattia
Andre DeMattia

Reputation: 630

ASP.Net Async Blocking UI

I have a ASP.Net Web Forms application that calls a WCF service hosted on IIS via a button click event inside a Ajax Update panel. When I click the button I call a WCF Async process that can take over 1 minute to return. I've noticed when the task is running and I open another tab in my browser the web page freezes/clocks until the long running task returns. I assume that the first task is locking the UI thread causing anyone else to use the web page to have to wait.

How can I run a task, update the UI with the results and not block the UI for other Tabs/Users?

Here is a snipit of code:

 protected void btnsearch_ServerClick(object sender, EventArgs e)
    {

        Page.RegisterAsyncTask(new PageAsyncTask(async () =>
        {
            DataSet ds;
            ds = await data.GetReportAsync();

            grdsummary.DataSource = ds.Tables[0];
            grdsummary.DataBind();
        }));

    }

I did try adding .ConfigureAwait(false) to the Async call but that didn't do anything.

Upvotes: 1

Views: 970

Answers (2)

Stephen Cleary
Stephen Cleary

Reputation: 456437

I assume that the first task is locking the UI thread causing anyone else to use the web page to have to wait.

This is ASP.NET; there's no UI thread.

Most likely, what is happening is that the session state is preventing multiple simultaneous requests.

Note that multiple users will not be affected; only multiple requests in the same session will be seiralized.

Upvotes: 2

Yoryll
Yoryll

Reputation: 13

Registering is one thing, Executing is one another :)

Just add an ExecuteRegisteredAsyncTasks call after and it should work fine, or please add the code where this call is done.

protected void btnSearch_Click(object sender, EventArgs e)
{
    Page.RegisterAsyncTask(new PageAsyncTask(async () =>
    {
        grdsummary.DataSource = await getSomeDataAsync();
        grdsummary.DataBind();
    }));
    Page.ExecuteRegisteredAsyncTasks();
}

Upvotes: 0

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