I have this scenario :

When a.aspx loads – I press the button1.
here is the question :
After pressing button1 – I Close the browser.
what happens now to the long work now ?
I guess it continues…
But the question is why ?
Doesnt Long work knows that his main ancestor thread was terminated ?
in fact also his father thread was terminated also ( b.aspx thread)
isnt there any relationship between long func to b.aspx / a.aspx ?
When you open a WebRequest to access b.aspx, you’re actually making an HTTP GET for that page. B.aspx does not know anything about a.aspx’s threads. However, when you close the browser, the HTTP channel from your browser to web server (running your button click handler) is terminated. The web server does not immediately notice this, however, and the thread responding to your click event continues to wait for the b.aspx WebRequest to complete and ultimately waits for your long-running b.aspx to render until server timeouts elapse.