c# - ManagedThreadId return same value for 2 threads -

please consider code:

textbox1.text = "enter thread current thread id : " + thread.currentthread.managedthreadid.tostring(); int result = 0; task t = task.factory.startnew(delegate      {         (int = 0; < 5; i++)         {             result = result + i;             system.threading.thread.sleep(1000);             this.invoke((action)(() => textbox1.text += environment.newline + result.tostring() + " current thread id : " + thread.currentthread.managedthreadid.tostring()));         }      },cancellationtoken.none, taskcreationoptions.none); 

i got result:

enter thread current thread id : 10

0 current thread id : 10

1 current thread id : 10

3 current thread id : 10

6 current thread id : 10

10 current thread id : 10

i ran code on windows form application. why thread.currentthread.managedthreadid return same value ui thread , task thread? code inside of task run in separate thread?

thanks

when did this.invoke told go ui thread. move thread.currentthread.managedthreadid outside of invoke , see different id ui thread.

also if want guarantee work done on thread pool thread either use task.run or pass startnew taskscheduler.default, if not possible have code invoked task.factory.startnew accedently run on ui thread. see startnew dangerous