How to set up TPalallel. & For, react and store values ​​in TList <T>?

In Delphi 10.1 Berlin, I would like to make the loop TParallel.&For

responsive.

I have a parallel loop similar to the TParallel.For example in question: Store values ​​in a TList as they are computed in a TParallel.For loop . The loop calculates the values ​​and stores those values ​​in TList<Real>

.

I am trying to run TParallel.&For

on a separate thread with TTask.Run

to make it responsive:

type
  TCalculationProject=class(TObject)
  private
    Task: ITask;
    ...
  public
    List: TList<Real>;
    ...
  end;

function TCalculationProject.CalculateListItem(const AIndex: Integer): Real;
begin
  //a function which takes a lot of calculation time
  //however in this example we simulate the calculation time and
  //use a simple alogorithm to verify the list afterwards
  Sleep(30);
  Result:=10*AIndex;
end;

procedure TCalculationProject.CalculateList;
begin
  List.Clear;

  Task:=TTask.Run(
    procedure
    var
      LoopResult: TParallel.TLoopResult;
      Res: Real;
      Lock: TCriticalSection;
    begin
      Lock:=TCriticalSection.Create;
      try
        LoopResult:=TParallel.&For(0, 1000-1,
          procedure(AIndex: Integer; LoopState: TParallel.TLoopState)
          begin
            Res:=CalculateListItem(AIndex);                              
            Lock.Enter;
            try
              List.Add(Res);
            finally
              Lock.Leave;
            end;
          end
        );
      finally
        Lock.Free;
      end;

      if LoopResult.Completed then
      begin
        TThread.Synchronize(TThread.Current,
          procedure
          begin
            SortList;
            ShowList;
          end
        );
      end;
    end
  );
end;

      

        
        
        
      

    

The problem is that the list is wrong on a random basis: there are duplicate values ​​in the list. For example:

list item 0: 0
list item 1: 10
list item 2: 20
list item 3: 20 <- incorrect
list item 4: 20 <- incorrect
list item 5: 50
....

      

        
        
        
      

    

Instead of a part, Lock.Enter

Lock.Leave

I also triedSynchronize

TThread.Synchronize(TThread.Current,
  procedure
  begin
    List.Add(Res);
  end
);

      

        
        
        
      

    

or

TThread.Synchronize(nil,
  procedure
  begin
    List.Add(Res);
  end
);

      

        
        
        
      

    

and Queue

TThread.Queue(TThread.Current,
  procedure
  begin
    List.Add(Res);
  end
);

      

        
        
        
      

    

or

TThread.Queue(nil,
  procedure
  begin
    List.Add(Res);
  end
);

      

        
        
        
      

    

but the problem remains. What am I doing wrong?