Print Watermark

Question

Hello,I'm using your PDF component to print a text watermark ("CONFIDENTIAL") on a page and I've followed your tutorial at https://help.syncfusion.com/file-formats/pdf/working-with-watermarksIt works but I have the following issues:1) I don't know how many pages is my PDF file, so I need to print the watermark on every page2) I need the text watermark to be vertically and horizontally centered on the page. I cannot use a fixed position (like in your example) because the page may be in Portrait or Landscape orientation, A4 or A3 size, etc.). How can I center it regardless of page size, orientation etc.?Thanks!

Surya Venkatesan · Answer

Hi Paolo,We have created a sample: https://www.syncfusion.com/downloads/support/directtrac/general/ze/PDF_SAmple_WatermarkAtCenter154317391
to achieve your requirement of adding watermark to be vertically and
horizontally centered on all pages in the PDF document.Kindly try the attached sample and let us know the result.Regards,Surya V

Paolo · Answer

Thanks, it works! But I want to rotate it, so I use:

graphics.RotateTransform(-45);

and it's not centered any longer. In other words, I need the rotation to be from the center, not from the top-left of the rectangle.

Thanks!

Surya Venkatesan · Answer

Hi Paolo,We have modified
the sample: https://www.syncfusion.com/downloads/support/directtrac/general/ze/PDF_SAmple_WM_WithRotateCenter-1891574735
accordingly for graphics rotation of -45degree. We recommend you modify the drawstring
of graphics bounds based on their rotation. For example, if graphics rotated to
-45degree, then we need to find the height of graphics by using diagonal (which
can be expressed with the following formula: d² = l² + w² ). Refer to the following
code snippet,

//Create
  graphics for the existing page
                 
  PdfGraphics graphics = loadedPage.Graphics;
                  float x = size.Width / 2 -
  loadedPage.Size.Width / 2;
                  float y = (float)Math.Sqrt((loadedPage.Size.Width
  * loadedPage.Size.Width) + (loadedPage.Size.Height * loadedPage.Size.Height))
  / 2f;
   
                  //Insert watermark text to PDF 
                 
  PdfGraphicsState state = graphics.Save();
                 
  graphics.SetTransparency(0.25f);
                  float angle = -45;
                 
  graphics.RotateTransform(angle);
                  x += (angle / 2);
                 
  graphics.DrawString(watermarkText, font, PdfBrushes.Red, new RectangleF(x, y, size.Width,
  size.Height));
                  graphics.Restore();

Kindly try the
attached sample and let us know the result.Regards,Surya V

Paolo · Answer

Hello,I tried it and I'm sorry it does not work. Or, better, it works but the watermark is not centered (I need it to be fully centered both vertically and horizontally). You can better see it if:You use a shorter watermark, for example 'PREVIEW'You use the attached PDF file (which is mostly blank)If you try your code with the attached PDF file and 'PREVIEW' as watermark, you'll get the attached output (see attached) and, as you can see, it's not centered.Attachment: Watermark_rotate_c7cd9e2a.zip

Surya Venkatesan · Answer

Hi Paolo,Thanks for
your update. We have modified a sample: https://www.syncfusion.com/downloads/support/directtrac/general/ze/PDF_SAmple_WaterMarkWithRotateCenter-830511359
to achieve your requirement of adding watermark to be vertically and
horizontally centered on all pages in the PDF document. The attached sample
generated output documents for your reference,

Short
  text output

Long Text
  output

Kindly try
the attached sample and let us know the result.Regards,Surya V

Paolo · Answer

Yes, it works, thank you!

Gowthamraj Kumar · Answer

Hi Paolo, 
  
Thank you for your update. Please let us know if you need any further assistance in this. 
 
Regards, 
Gowthamraj K