知识库

var
  i, t, l     : Integer;
begin
  btnDemo.Enabled := False;
  t := Self.Top;
  l := Self.Left;

  for i := 0 to 20 do
  begin

    case (i mod 4) of
    0:
      begin
        Self.Top  := t + 2;
        Self.Left := l + 2;
      end;
    1:
      begin
        Self.Top  := t + 2;
        Self.Left := l - 2;
      end;
    2:
      begin
        Self.Top  := t - 2;
        Self.Left := l - 2;
      end;
    3:
      begin
        Self.Top  := t - 2;
        Self.Left := l + 2;
      end;
    end;
    Application.ProcessMessages;

    //Sleep(50);
    SleepEx(50, True);
  end;
  Self.Top  := t;
  Self.Left := l;

  btnDemo.Enabled := True;