How to add Annotation to an existing PDF

[devang.patel@altegrahealth.com]

Hello,

I am trying to add annotation on first page to the existing PDF using below code.

PdfPageBase page = (PdfPageBase)ExistingImagePDF.Pages[0];
PdfFont font = new PdfFont(PdfFontFamily.Helvetica, 13);
string text = "HelloWorld";
PointF point = new PointF(200, 100);
page.Canvas.DrawString(text, font, PdfBrushes.CadetBlue, point);

PdfTextMarkupAnnotation annotation1 = new PdfTextMarkupAnnotation("Administrator", "Some Default Text", text, new PointF(0, 0), font);
annotation1.Border = new PdfAnnotationBorder(0.75f);
annotation1.TextMarkupColor = Color.Green;

annotation1.Location = new PointF(point.X + ExistingImagePDF.PageSettings.Margins.Left, point.Y + ExistingImagePDF.PageSettings.Margins.Left);
(page as PdfNewPage).Annotations.Add(annotation1);

but I am getting object reference error on the last line because (page as PdfNewPage) is giving as NULL.

Can anyone suggest how to get first page object ?

[Gary.zhang]

Hello,

Thanks for your inquiry. For an existing PDF, you need to use page.AnnotationsWidget.Add method.

Code: Select all

 page.AnnotationsWidget.Add(annotation1);


Sincerely,
Gary
E-iceblue support team

[devang.patel@altegrahealth.com]

Thank you for your reply.

I have already tried the same thing but it is not showing in the PDF.

[Gary.zhang]

Hello,

Thanks for your prompt response. Could you please provide us the document you were trying and point out where the place the annotation needs to be added? And we will provide you the solution accordingly.

Thanks,
Gary
E-iceblue support team