procedure TMainForm.btnAPIClick(Sender: TObject);
var
  LTDResult: Integer;
begin
  TaskDialog(0, HInstance,
    PChar('The Title'),
    PChar('These are the main instructions'),
    PChar('This is another content'),
    TDCBF_OK_BUTTON or TDCBF_CANCEL_BUTTON,
    TD_INFORMATION_ICON, @LTDResult);
  case LTDResult of
    IDOK:
      begin
        ShowMessage('Clicked OK');
      end;
    IDCANCEL:
      begin
        ShowMessage('Clicked Cancel');
      end;
  end;
end;

object tdSimple: TTaskDialog
  Caption = 'The question'
  CommonButtons = [tcbYes, tcbNo]
  DefaultButton = tcbYes
  ExpandButtonCaption = 'More information'
  ExpandedText = 'Yes, you have to decide something about this question...' + ' but I cannot help you a lot'
  Flags = [tfUseHiconMain, tfUseHiconFooter, tfVerificationFlagChecked]
  FooterIcon = 4
  FooterText = 'This is an important question...'
  Text = 'To be or not to be, this is the question. To be?'
  Title = 'William ask:'
end

procedure TMainForm.btnSimpleClick(Sender: TObject);
begin
  tdSimple.Execute; //show the taskdialog
  if tdSimple.ModalResult = mrYes then
    ShowMessage('yes')
  else
    ShowMessage('no')
end;

object tdRadioButtons: TTaskDialog
  Caption = 'The question'
  DefaultButton = tcbYes
  ExpandButtonCaption = 'More information'
  ExpandedText = 
    'Yes, you have to decide something about this question... ' + 'but I cannot help you a lot'
  Flags = [tfUseHiconMain, tfUseHiconFooter, tfVerificationFlagChecked]
  FooterIcon = 4
  FooterText = 'This is an important question...'
  RadioButtons = <
    item
      Caption = 'Yes, I want to buy this book'
    end
    item
      Caption = 'No, this book is awful'
    end
    item
      Caption = 'Maybe in the future'
    end>
  Text = 'Do you wanna buy "The Tragedy of Hamlet"?'
  Title = 'William ask:'
end

procedure TMainForm.btnRadioClick(Sender: TObject);
begin
  tdRadioButtons.Execute;
  if tdRadioButtons.ModalResult = mrOk then
    ShowMessage('Selected radio button ' + tdRadioButtons.RadioButton.ID.ToString);
end;

procedure TMainForm.btnConfirmClick(Sender: TObject);
var
  LFileName: string;
  LGSearch: String;
const
  GOOGLE_SEARCH = 99;
begin
  LFileName := 'MyCoolProgram.exe';
  tdConfirm.Buttons.Clear;
  tdConfirm.Title := 'Confirm Removal';
  tdConfirm.Caption := 'My fantastic folder';
  tdConfirm.Text :=
    Format('Are you sure that you want to remove ' + 'the file named "%s"?', [LFileName]);
  tdConfirm.CommonButtons := [];
  with TTaskDialogButtonItem(tdConfirm.Buttons.Add) do
  begin
    Caption := 'Remove';
    CommandLinkHint := Format('Delete file %s from the folder.', [LFileName]);
    ModalResult := mrYes;
  end;
  with TTaskDialogButtonItem(tdConfirm.Buttons.Add) do
  begin
    Caption := 'Keep';
    CommandLinkHint := 'Keep the file in the folder.';
    ModalResult := mrNo;
  end;

  if TPath.GetExtension(LFileName).ToLower.Equals('.exe') then
  begin
    with TTaskDialogButtonItem(tdConfirm.Buttons.Add) do
    begin
      Caption := 'Google search';
      CommandLinkHint := 'Let''s Google tell us what ' + 'this program is.';
      ModalResult := GOOGLE_SEARCH;
    end;
  end;

  tdConfirm.Flags := [tfUseCommandLinks];
  tdConfirm.MainIcon := tdiInformation;

  if tdConfirm.Execute then
  begin
    case tdConfirm.ModalResult of
      mrYes:
        ShowMessage('Deleted');
      mrNo:
        ShowMessage(LFileName + 'has been preserved');
      GOOGLE_SEARCH:
        begin
          LGSearch := Format('https://www.google.it/#q=%s', [LFileName]);
          ShellExecute(0, 'open', PChar(LGSearch), nil, nil, SW_SHOWNORMAL);
        end;
    end; //case
  end; //if
end;

object tdProgress: TTaskDialog
  Caption = 'Please wait'
  CommonButtons = [tcbCancel]
  ExpandButtonCaption = 'More'
  ExpandedText = 
    'A prime number (or a prime) is a natural number greater'+' than 1 that has no positive divisors other than 1 ' + 'and itself.'
  Flags = [tfAllowDialogCancellation, tfShowProgressBar, 
tfCallbackTimer]
  FooterIcon = 3
  FooterText = 'Please wait while we are calculate prime numbers'
  Text = 'Let'#39's calculate prime numbers up to 1000'
  Title = 'Calculating prime numbers...'
  VerificationText = 'Remember my choice'
  OnButtonClicked = tdProgressButtonClicked
  OnTimer = tdProgressTimer
end

const
  MAX_NUMBERS = 1000;
  NUMBERS_IN_A_SINGLE_STEP = 50;

procedure TMainForm.tdProgressButtonClicked(Sender: TObject;
  ModalResult: TModalResult; var CanClose: Boolean);
begin
  if not FFinished then
  begin
    tdProgress.OnTimer := nil;
    ShowMessage('Calculation aborted by user');
    CanClose := True;
  end;
end;

procedure TMainForm.tdProgressTimer(Sender: TObject; TickCount: Cardinal;
  var Reset: Boolean);
var
  I: Integer;
begin
  for I := 1 to NUMBERS_IN_A_SINGLE_STEP do
  begin
    if IsPrimeNumber(FCurrNumber) then
      Inc(FPrimeNumbersCount);
    tdProgress.ProgressBar.Position := FCurrNumber * 100 div MAX_NUMBERS;
    Inc(FCurrNumber);
  end;

  FFinished := FCurrNumber >= MAX_NUMBERS;
  if FFinished then
  begin
    tdProgress.OnTimer := nil;
    tdProgress.ProgressBar.Position := 100;
    ShowMessage('There are ' + FPrimeNumbersCount.ToString + ' prime numbers up to ' + MAX_NUMBERS.ToString);
  end;
end;

procedure TMainForm.btnProgressClick(Sender: TObject);
begin
  FCurrNumber := 1;
  FFinished := False;
  FPrimeNumbersCount := 0;
  tdProgress.ProgressBar.Position := 0;
  tdProgress.OnTimer := tdProgressTimer;
  tdProgress.Execute;
end;

procedure TMainForm.btnCheckWinVerClick(Sender: TObject);
var
  LTaskDialog: TTaskDialog;
begin
  if (Win32MajorVersion >= 6) and ThemeServices.ThemesEnabled then
  begin
    LTaskDialog := TTaskDialog.Create(Self);
    try
      LTaskDialog.Caption := 'MY Fantastic Application';
      LTaskDialog.Title := 'The Cook Task Dialog!';
      LTaskDialog.Text :=
        'This is a Task Dialog, so I''m on Vista ' + 'or better with themes enabled';
      LTaskDialog.CommonButtons := [tcbOk];
      LTaskDialog.Execute;
    finally
      LTaskDialog.Free;
    end
  end
  else
  begin
    ShowMessage('This is an old and boring ShowMEssage, ' + 'here only to support old Microsoft Windows OS ' + '(XP and below)');
  end;
end;