Enable and disable button while running thread in asp.net

Question

In the button click in web application asp.net, i have created a thread.Inside the thread, I am trying to disable the button and do some background jobs. Background jobs working perfectly but button disabling is not working. MY CODE IS:

private void generteBtn_Click(object sender, EventArgs e)
{
   new Thread (() =>
    {
       btn.enabled = false;
       // thread work start here;
       //emailing
    }.start();
     
}

My question is how can I disable buttons while the threads are working and re enable generteBtn_Click after the threads finished.

You need to understand the working Asp.net first which can help you. — शेखर, Dec 25 '21 at 12:00
As a general rule, in all, if not most, .NET UI frameworks, you cannot manipulate or access any UI element in a background thread. — Enigmativity, Dec 26 '21 at 02:44

score 0 · Answer 1 · answered Dec 26 '21 at 13:36

0

because the thread that you created here is not the UI thread and to access any element in the UI thread you can use:

Application.Current.Dispatcher.Invoke(() =>
{
    btn.enabled = false;
});

and for more details you can check these links:

1- How do I get the UI thread's Dispatcher?

2- Dispatcher.Dispatch on the UI thread

answered Dec 26 '21 at 13:36

Kerollos Melad

64
1
7

and also you should use Task instead of Thread – Kerollos Melad Dec 26 '21 at 13:36
We are talking web apps here, not winforms or wpf :-) – Peter Bons Dec 28 '21 at 09:45
still the same, this thread has no access to other thread objects, so he needs to use dispatcher, or he can update the button outside the action before the thread starts working. – Kerollos Melad Dec 28 '21 at 14:29

score 0 · Answer 2 · answered Dec 26 '21 at 21:26

Hide/show the buttion BEFORE you start the next process/thread.

eg:

       btn.enabled = false;
      new Thread (() =>
      {
      // thread work start here;
      //emailing
      }.start();

That way, the button is disabled, process starts, as always then a whole new fresh copy of the web page is then sent back to the client side.

If you need to update that page? Then you have really only 2 practial choices.

You can start a timer on the page - call a ajax routine, and it will have to check say some session() value that the process sets = "done".

The other way would be to introduce signalR into your applcation.

https://learn.microsoft.com/en-us/aspnet/signalr/overview/getting-started/introduction-to-signalr#:~:text=What%20is%20SignalR%3F%20ASP.NET%20SignalR%20is%20a%20library,process%20of%20adding%20real-time%20web%20functionality%20to%20applications.

I have a number of processing routines. I start the process, and the I start a timeer on the page. It re-freshens a update panel every 1 second until such time the session("MyProcessDone") = true, and then I stop the timer at that point (and of course update the spinner/animated gif). So, you can start a timer on the web page - and check some session() value, or as noted, introduce signalR into your applicaton.

Enable and disable button while running thread in asp.net

2 Answers2