multithreading - C# callback on new thread -

i having trouble creating callback on newly started thread.

i have 2 classes, api, , form.cs. start thread running method in api, form.cs, want notify method in form.cs inside method in api.

i familiar delegation in obj-c, not in c#.

i included relevant code.

public partial class main: form {      private api connect = new api();      private void startstopbutton_click(object sender, eventargs e)     {         //new thread         thread threadconnect = new thread(connect.startattemptingwithusername);         threadconnect.start();     }      public void attemptingwithpasswordmessage(string password)     {         // want notify method api     } }  class api : useragent {     public void startattemptingwithusername()     {         _shouldstop = false;         while (!_shouldstop)         {             console.writeline(username);             // how notify attemptingwithpasswordmessage here?             system.threading.thread.sleep(1000);         }     } } 

provide event other class, , fire event whenever relevant based on processing:

class api : useragent {     public event action<string> someevent;//todo give better name     public void startattemptingwithusername()     {         _shouldstop = false;         while (!_shouldstop)         {             console.writeline(username);             var handler = someevent;             if (handler != null)                 handler("asdf");             // how notify attemptingwithpasswordmessage here?             system.threading.thread.sleep(1000);         }     } } 

then add handler event: (and marshal ui thread)

private void startstopbutton_click(object sender, eventargs e) {     //new thread     thread threadconnect = new thread(connect.startattemptingwithusername);     threadconnect.start();     connect.someevent += (data) => invoke(         new action(()=>attemptingwithpasswordmessage(data))); }