Manage Markup Annotations with New DevExpress PDF Document API
- 8 minutes to read
Markup annotations in PDF files allow users to add comments, highlights, and other visual elements to a document. The PDF Document API supports the following markup annotation types: text, drawing, stamp, and redaction.
The DevExpress PDF Document API allows you to create and delete annotations, edit their content, and add related comments and reviews. Use Page.Annotations to access all annotations on a page, and PdfDocument.Pages to obtain the corresponding Page instance.
This topic describes markup annotations. Refer to the following help topics for information about other annotation types:
- Annotations in PDF Documents - lists all annotation types and their common features.
- Redaction Annotations - describes redaction annotations.
- Link Annotations - describes link annotations.
Create Text Markup Annotations
Text markup annotations include the following types:
The following code snippet creates two annotations - a text highlight and a free text annotation:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
List<TextSearchInfo> results = document.FindText("external PDF Viewer").ToList();
foreach (var match in results.SelectMany(x => x.Matches)) {
var rects = match.MatchFragments
.Select(x => x.Rectangle)
.ToList();
TextMarkupAnnotation textMarkupAnnotationCommon = new(rects) {
Color = PdfColor.Yellow,
Title = "Brian Zetc",
Content = "This is a highlight annotation.",
Type = TextMarkupAnnotationType.Highlight
};
document.Pages[match.PageIndex].Annotations.Add(textMarkupAnnotationCommon);
document.Pages[match.PageIndex].Annotations.Add(new FreeTextAnnotation(new RectangleF(10, 50, 100, 50)) {
Color = PdfColor.Red,
Title = "Brian Zetc",
Content = "This is a free text annotation."
});
}
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));
Create Drawing Annotations
The following drawing annotation types are available:
The following code snippet creates two annotations - circle and ink:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
List<TextSearchInfo> results = document.FindText("Type 3 Fonts").ToList();
foreach (var match in results.SelectMany(x => x.Matches)) {
var rects = match.MatchFragments
.Select(x => x.Rectangle)
.ToList();
foreach (var rect in rects) {
CircleAnnotation circleAnnotation = new CircleAnnotation(rect.BoundingBox)
{
Color = PdfColor.Red,
Title = "Brian Zetc",
Content = "This is a circle annotation."
};
document.Pages[match.PageIndex].Annotations.Add(circleAnnotation);
}
}
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));
Create Rubber Stamp Annotations
RubberStampAnnotation usually indicates document progress or review status, such as “Approved,” “Draft”, “Confidential”, or “Rejected”. The DevExpress PDF Document API supports three stamp annotation types: static, dynamic, and custom.
Create Simple Rubber Stamp Annotations
Pass one of the RubberStampAnnotationIconName class fields to the RubberStampAnnotation.IconName property to define a built-in static icon for rubber stamp.
The following code snippet creates a Top Secret rubber stamp:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
RubberStampAnnotation rubberStampAnnotation = new RubberStampAnnotation(new RectangleF(10, 550, 240, 50)) {
Title = "Jesse Faden",
IconName = RubberStampAnnotationIconName.TopSecret,
CreationDate = DateTime.Now,
Subject = "Approval",
Content = "This document has been approved."
};
document.Pages[0].Annotations.Add(rubberStampAnnotation);
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));
Create Dynamic Rubber Stamp Annotations
To create a dynamic rubber stamp, set RubberStampAnnotation.IconName to one of the following values:
| Icon Name | Rubber Stamp |
|---|---|
| DReviewed |  |
| DRevised |  |
| DApproved |  |
| DConfidential |  |
| DReceived |  |
Use the Title and CreationDate properties to display additional information.
The following code snippet creates a Reviewed dynamic stamp:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
RubberStampAnnotation rubberStampAnnotation = new RubberStampAnnotation(new RectangleF(10, 550, 240, 50), RubberStampAnnotationIconName.DReviewed)
{
Title = "Jesse Faden",
CreationDate = DateTime.Now,
Subject = "Approval",
Content = "This document is reviewed."
};
document.Pages[0].Annotations.Add(rubberStampAnnotation);
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));
Create an Annotation with a Custom Stamp
You can generate a stamp that displays another document’s page. Pass the a file and a page number as the RubberStampAnnotation.SetCustomIcon method parameters to create a custom stamp.
The following code snippet generates a custom stamp from another document:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
RubberStampAnnotation rubberStampAnnotation = new RubberStampAnnotation(new RectangleF(10, 550, 240, 50))
{
Title = "Jesse Faden",
CreationDate = DateTime.Now,
Subject = "Approval"
};
rubberStampAnnotation.SetCustomIcon(new FileStream("document.pdf", FileMode.Open), 3);
document.Pages[0].Annotations.Add(rubberStampAnnotation);
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));
Add Comments
Call the AddReply(Page, String, String) method to add a comment to a markup annotation.
The following code snippet adds a nested comment to a TextAnnotation:
static void Main(string[] args) {
FileStream fs = File.OpenRead("Invoice.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
List<TextAnnotation> textAnnotations = FindTextAnnotations(document, "Brian Zetc");
TextAnnotation comment = textAnnotations[0];
comment.AddReply(document.Pages[0], "Cardle Anita L", "Thank you!");
document.Save(new FileStream("Invoice2.pdf", FileMode.Create, FileAccess.Write));
}
static List<TextAnnotation> FindTextAnnotations(PdfDocument document, string searchText) {
var result = new List<TextAnnotation>();
foreach (var page in document.Pages) {
foreach (var annotation in page.Annotations) {
if (annotation is TextAnnotation textAnnotation) {
bool matchByTitle =
!string.IsNullOrEmpty(textAnnotation.Title) &&
textAnnotation.Title.IndexOf(searchText, StringComparison.OrdinalIgnoreCase) >= 0;
bool matchByContent =
!string.IsNullOrEmpty(textAnnotation.Content) &&
textAnnotation.Content.IndexOf(searchText, StringComparison.OrdinalIgnoreCase) >= 0;
if (matchByTitle || matchByContent)
result.Add(textAnnotation);
}
}
}
return result;
}
Add Reviews
Call the MarkupAnnotation.AddReview method to add a review to a markup annotation. The MarkupAnnotation.GetReviewHistory method returns all annotation reviews.
To remove all reviews, call the MarkupAnnotation.ClearReviews method.
The following code snippet adds reviews to annotations made by a specific author:
FileStream fs = File.OpenRead("Demo.pdf");
var options = new LoadOptions();
PdfDocument document = new PdfDocument(fs, options);
var annotationsToReply = document.Pages[0].Annotations
.OfType<TextMarkupAnnotation>()
.Where(a => a.Content == "This is a highlight annotation.")
.ToList();
foreach (var annotation in annotationsToReply) {
annotation.AddReview(document.Pages[0], "Cardle Anita L", ReviewStatus.Accepted);
}
document.Save(new FileStream("Demo2.pdf", FileMode.Create, FileAccess.Write));