Accessing all threads instantiated

Put "MyLogin;" in the execute method of the thread?

Look at the code below..
You'll need to hold the reference to each thread using different variables, to do this you can use an array.
This array should be filled with the thread instances (you can do this on OnCreate event). Assuming that the threads are started suspendedly (does not start until Resume is called), you can start the thread any time using the StartLogin method. This method will iterate through all threads on the array and run it one by one, after that it will empty the array (so that if StartLogin is called again, it does not give an access violation).

type
  TMyThread = ...
  ..
  end;
 
  TMyThreadArray = array of TMyThread;
 
  TForm1 = class(TForm)
  ..
  private
    FLoginThreads: TMyThreadArray;
    procedure StartLogin;
  ..
  ..
  end;
 
..
..
procedure TForm1.Form1Create(Sender: TObject);
begin
  SetLength(FLoginThreads, 3);
  FLoginThreads[0] := TMyThread.Create('login1');
  FLoginThreads[1] := TMyThread.Create('login2');
  FLoginThreads[2] := TMyThread.Create('login3');
end;
 
procedure TForm1.StartLogin;
var
  MyThread: TMyThread;
begin
  for MyThread in FLoginThreads do
  begin
    MyThread.Resume;
  end;
  FLoginThreads := nil;
end;

Select allOpen in new window

ok I understood, but in the line "for MyThread in FLoginThreads do" the following error occurs:

"operator not applicable to this operand type"

why this occurs ?