c# - Notifying about task finishing its work -

i'm thinking of simple way of reacting on task finishing work. came following solution (paste winforms application single button test):

public partial class form1 : form {     private thread thread;      public void dofinishwork() {          // [4]          // ui thread - waiting thread finalize work         thread.join();          // checking, if finished work         messagebox.show("thread state: " + thread.isalive.tostring());     }      public void dowork() {          // [2]         // working hard         thread.sleep(1000);     }      public void finishwork() {          // [3]         // asynchronously notifying form in main thread, work done         delegate del = new action(dofinishwork);         this.begininvoke(del);          // finalizing work - should switched         // @ point main thread         thread.sleep(1000);     }      public form1()     {         initializecomponent();     }      private void button1_click(object sender, eventargs e) {          // [1]         // schedule task         threadstart start = new threadstart(dowork);         // schedule notification finishing work         start += finishwork;          thread = new thread(start);         thread.start();     } } 

this meant simple cancel scenario, there 1 thread, running in parallel ui thread.

is there simpler (or more thread-safe) way of implementing kind of notification thread?

please take consideration 2 facts:

• the way can terminate thread abort (that's because have no control on being done in thread - 3rd party code)
• thus, cannot use backgroundworker, because provides way of graceful termination.

is there simpler (or more thread-safe) way of implementing kind of notification thread?

yes, use tpl , let framework worry managing thread

task.startnew(() => {    // stuff }).continuewith((task) => {    // stuff after have finished doing other stuff }); 

or alternatively, since working winforms, use backgroundworker , handle runworkercompleted event.

i mistook notion of kill cancel - there no reliable way of killing thread in .net, documentation suggests using abort more or less gamble , gives absolutely no guarentees thread killed. also, leave thread and, consequence, application in unpredictable state if willing take risk that's you.

one alternative let thread play out ignore results, depending on size of task might not big deal.