[Printpreview] Pageborder

[Jens01]

Dear Kambiz,

among the printerborder I want draw the pageborder on the preview. But after now 3 hours I know it not so easy as I hoped.
I want to draw them as the printerborder with light-gray dotline. Are there a OnPaint-Event I can use?

Thanking you in anticipation
Jens

[Kambiz]

Set Background property to true, then write a handler for OnBackground event to draw the border in preview.

If you want to draw the border in print, you should use OnPrintBackground event.

I hope this helps.

[Jens01]

I tried it with OnBackground. Yes it draws the border but I want to switch it on and off the same time with ShowPrintableArea. But OnBackground doesnt fire when the Paperwiew is refreshed. It allways draws the paperborders.

[EDIT]
The solution is UpdateBackground!

[Kambiz]

You can also set ShowPrintableArea and Background properties at the same time.

[Jens01]

Yes, I did but if I click the button to switch ShowPrintableArea it doesnt fire the OnBackground-Event. Only with UpdateBackground it works.

Code: Select all

procedure TPreviewFenster.btnAreaClick(Sender: TObject);
begin
  PrintPreview1.ShowPrintableArea := not PrintPreview1.ShowPrintableArea;
  PrintPreview1.UpdateBackground;
end;

procedure TPreviewFenster.PrintPreview1Background(Sender: TObject; PageNo: Integer;
  Canvas: TCanvas);
begin
  if PrintPreview1.ShowPrintableArea then
  with Canvas do
  begin
    with PageBoundsAfterMargin do
    begin
      // We are going to draw a rectangle on the page to distinguish the page's
      // margin. The margin is already calculated in the GeneratePages function.
      Pen.Mode := pmMask;
      Pen.Width := 0;
      Pen.Style := psDot;
      Pen.Color := PrintPreview1.PrintableAreaColor;
      Rectangle(Left, Top, Right, Bottom);
    end;
  end;
end;

function TPreviewFenster.PageBoundsAfterMargin: TRect;
begin
  Result := PrintPreview1.GetPageSetupParameters(PageSetupDialog);
end;

[Kambiz]

Usually all pages share a single background (for example, your case). Therefore, the background is drawn only once to save a bit memory and CPU time. And, if it needs to be updated, UpdateBackground is called.